draft-ietf-detnet-security-11.txt   draft-ietf-detnet-security-12.txt 
Internet Engineering Task Force T. Mizrahi Internet Engineering Task Force E. Grossman, Ed.
Internet-Draft HUAWEI Internet-Draft DOLBY
Intended status: Informational E. Grossman, Ed. Intended status: Informational T. Mizrahi
Expires: February 15, 2021 DOLBY Expires: April 5, 2021 HUAWEI
August 14, 2020 A. Hacker
MISTIQ
October 2, 2020
Deterministic Networking (DetNet) Security Considerations Deterministic Networking (DetNet) Security Considerations
draft-ietf-detnet-security-11 draft-ietf-detnet-security-12
Abstract Abstract
A DetNet (deterministic network) provides specific performance A DetNet (deterministic network) provides specific performance
guarantees to its data flows, such as extremely low data loss rates guarantees to its data flows, such as extremely low data loss rates
and bounded latency. As a result, securing a DetNet requires that in and bounded latency. As a result, securing a DetNet requires that in
addition to the best practice security measures taken for any addition to the best practice security measures taken for any
mission-critical network, additional security measures may be needed mission-critical network, additional security measures may be needed
to secure the intended operation of these novel service properties. to secure the intended operation of these novel service properties.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 15, 2021. This Internet-Draft will expire on April 5, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Abbreviations and Terminology . . . . . . . . . . . . . . . . 6 2. Abbreviations and Terminology . . . . . . . . . . . . . . . . 6
3. Security Considerations for DetNet Component Design . . . . . 6 3. Security Considerations for DetNet Component Design . . . . . 6
3.1. Resource Allocation . . . . . . . . . . . . . . . . . . . 7 3.1. Resource Allocation . . . . . . . . . . . . . . . . . . . 7
3.2. Explicit Routes . . . . . . . . . . . . . . . . . . . . . 7 3.2. Explicit Routes . . . . . . . . . . . . . . . . . . . . . 7
3.3. Redundant Path Support . . . . . . . . . . . . . . . . . 7 3.3. Redundant Path Support . . . . . . . . . . . . . . . . . 8
3.4. Timing (or other) Violation Reporting . . . . . . . . . . 8 3.4. Timing (or other) Violation Reporting . . . . . . . . . . 9
4. DetNet Security Considerations Compared With DiffServ 4. DetNet Security Considerations Compared With DiffServ
Security Considerations . . . . . . . . . . . . . . . . . . . 9 Security Considerations . . . . . . . . . . . . . . . . . . . 9
5. Security Threats . . . . . . . . . . . . . . . . . . . . . . 10 5. Security Threats . . . . . . . . . . . . . . . . . . . . . . 10
5.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 10 5.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 11
5.2. Threat Analysis . . . . . . . . . . . . . . . . . . . . . 11 5.2. Threat Analysis . . . . . . . . . . . . . . . . . . . . . 12
5.2.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . 11 5.2.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2.2. DetNet Flow Modification or Spoofing . . . . . . . . 11 5.2.2. DetNet Flow Modification or Spoofing . . . . . . . . 12
5.2.3. Resource Segmentation (Inter-segment Attack) . . . . 12 5.2.3. Resource Segmentation (Inter-segment Attack) . . . . 12
5.2.4. Packet Replication and Elimination . . . . . . . . . 12 5.2.4. Packet Replication and Elimination . . . . . . . . . 12
5.2.4.1. Replication: Increased Attack Surface . . . . . . 12 5.2.4.1. Replication: Increased Attack Surface . . . . . . 12
5.2.4.2. Replication-related Header Manipulation . . . . . 12 5.2.4.2. Replication-related Header Manipulation . . . . . 12
5.2.5. Path Choice . . . . . . . . . . . . . . . . . . . . . 13 5.2.5. Controller Plane . . . . . . . . . . . . . . . . . . 13
5.2.5.1. Path Manipulation . . . . . . . . . . . . . . . . 13 5.2.5.1. Path Choice Manipulation . . . . . . . . . . . . 13
5.2.5.2. Path Choice: Increased Attack Surface . . . . . . 13 5.2.5.2. Compromised Controller . . . . . . . . . . . . . 14
5.2.6. Controller Plane . . . . . . . . . . . . . . . . . . 13 5.2.6. Reconnaissance . . . . . . . . . . . . . . . . . . . 14
5.2.6.1. Control or Signaling Packet Modification . . . . 13 5.2.7. Time Synchronization Mechanisms . . . . . . . . . . . 14
5.2.6.2. Control or Signaling Packet Injection . . . . . . 13
5.2.7. Scheduling or Shaping . . . . . . . . . . . . . . . . 13
5.2.7.1. Reconnaissance . . . . . . . . . . . . . . . . . 13
5.2.8. Time Synchronization Mechanisms . . . . . . . . . . . 13
5.3. Threat Summary . . . . . . . . . . . . . . . . . . . . . 14 5.3. Threat Summary . . . . . . . . . . . . . . . . . . . . . 14
6. Security Threat Impacts . . . . . . . . . . . . . . . . . . . 14 6. Security Threat Impacts . . . . . . . . . . . . . . . . . . . 15
6.1. Delay-Attacks . . . . . . . . . . . . . . . . . . . . . . 17 6.1. Delay-Attacks . . . . . . . . . . . . . . . . . . . . . . 18
6.1.1. Data Plane Delay Attacks . . . . . . . . . . . . . . 17 6.1.1. Data Plane Delay Attacks . . . . . . . . . . . . . . 18
6.1.2. Controller Plane Delay Attacks . . . . . . . . . . . 18 6.1.2. Controller Plane Delay Attacks . . . . . . . . . . . 19
6.2. Flow Modification and Spoofing . . . . . . . . . . . . . 18 6.2. Flow Modification and Spoofing . . . . . . . . . . . . . 19
6.2.1. Flow Modification . . . . . . . . . . . . . . . . . . 18 6.2.1. Flow Modification . . . . . . . . . . . . . . . . . . 19
6.2.2. Spoofing . . . . . . . . . . . . . . . . . . . . . . 18 6.2.2. Spoofing . . . . . . . . . . . . . . . . . . . . . . 19
6.2.2.1. Dataplane Spoofing . . . . . . . . . . . . . . . 18 6.2.2.1. Dataplane Spoofing . . . . . . . . . . . . . . . 19
6.2.2.2. Controller Plane Spoofing . . . . . . . . . . . . 19 6.2.2.2. Controller Plane Spoofing . . . . . . . . . . . . 20
6.3. Segmentation Attacks (injection) . . . . . . . . . . . . 19 6.3. Segmentation Attacks (injection) . . . . . . . . . . . . 20
6.3.1. Data Plane Segmentation . . . . . . . . . . . . . . . 19 6.3.1. Data Plane Segmentation . . . . . . . . . . . . . . . 20
6.3.2. Controller Plane Segmentation . . . . . . . . . . . . 19 6.3.2. Controller Plane Segmentation . . . . . . . . . . . . 20
6.4. Replication and Elimination . . . . . . . . . . . . . . . 20 6.4. Replication and Elimination . . . . . . . . . . . . . . . 21
6.4.1. Increased Attack Surface . . . . . . . . . . . . . . 20 6.4.1. Increased Attack Surface . . . . . . . . . . . . . . 21
6.4.2. Header Manipulation at Elimination Routers . . . . . 20 6.4.2. Header Manipulation at Elimination Routers . . . . . 21
6.5. Control or Signaling Packet Modification . . . . . . . . 20 6.5. Control or Signaling Packet Modification . . . . . . . . 21
6.6. Control or Signaling Packet Injection . . . . . . . . . . 20 6.6. Control or Signaling Packet Injection . . . . . . . . . . 21
6.7. Reconnaissance . . . . . . . . . . . . . . . . . . . . . 20 6.7. Reconnaissance . . . . . . . . . . . . . . . . . . . . . 21
6.8. Attacks on Time Sync Mechanisms . . . . . . . . . . . . . 21 6.8. Attacks on Time Sync Mechanisms . . . . . . . . . . . . . 22
6.9. Attacks on Path Choice . . . . . . . . . . . . . . . . . 21 6.9. Attacks on Path Choice . . . . . . . . . . . . . . . . . 22
7. Security Threat Mitigation . . . . . . . . . . . . . . . . . 21 7. Security Threat Mitigation . . . . . . . . . . . . . . . . . 22
7.1. Path Redundancy . . . . . . . . . . . . . . . . . . . . . 21 7.1. Path Redundancy . . . . . . . . . . . . . . . . . . . . . 22
7.2. Integrity Protection . . . . . . . . . . . . . . . . . . 22 7.2. Integrity Protection . . . . . . . . . . . . . . . . . . 22
7.3. DetNet Node Authentication . . . . . . . . . . . . . . . 22 7.3. DetNet Node Authentication . . . . . . . . . . . . . . . 23
7.4. Dummy Traffic Insertion . . . . . . . . . . . . . . . . . 23 7.4. Dummy Traffic Insertion . . . . . . . . . . . . . . . . . 24
7.5. Encryption . . . . . . . . . . . . . . . . . . . . . . . 23 7.5. Encryption . . . . . . . . . . . . . . . . . . . . . . . 24
7.5.1. Encryption Considerations for DetNet . . . . . . . . 24 7.5.1. Encryption Considerations for DetNet . . . . . . . . 24
7.6. Control and Signaling Message Protection . . . . . . . . 25 7.6. Control and Signaling Message Protection . . . . . . . . 25
7.7. Dynamic Performance Analytics . . . . . . . . . . . . . . 25 7.7. Dynamic Performance Analytics . . . . . . . . . . . . . . 26
7.8. Mitigation Summary . . . . . . . . . . . . . . . . . . . 26 7.8. Mitigation Summary . . . . . . . . . . . . . . . . . . . 27
8. Association of Attacks to Use Cases . . . . . . . . . . . . . 27 8. Association of Attacks to Use Cases . . . . . . . . . . . . . 28
8.1. Association of Attacks to Use Case Common Themes . . . . 27 8.1. Association of Attacks to Use Case Common Themes . . . . 28
8.1.1. Sub-Network Layer . . . . . . . . . . . . . . . . . . 27 8.1.1. Sub-Network Layer . . . . . . . . . . . . . . . . . . 28
8.1.2. Central Administration . . . . . . . . . . . . . . . 28 8.1.2. Central Administration . . . . . . . . . . . . . . . 29
8.1.3. Hot Swap . . . . . . . . . . . . . . . . . . . . . . 28 8.1.3. Hot Swap . . . . . . . . . . . . . . . . . . . . . . 29
8.1.4. Data Flow Information Models . . . . . . . . . . . . 29 8.1.4. Data Flow Information Models . . . . . . . . . . . . 30
8.1.5. L2 and L3 Integration . . . . . . . . . . . . . . . . 29 8.1.5. L2 and L3 Integration . . . . . . . . . . . . . . . . 30
8.1.6. End-to-End Delivery . . . . . . . . . . . . . . . . . 29 8.1.6. End-to-End Delivery . . . . . . . . . . . . . . . . . 30
8.1.7. Replacement for Proprietary Fieldbuses and Ethernet- 8.1.7. Replacement for Proprietary Fieldbuses and Ethernet-
based Networks . . . . . . . . . . . . . . . . . . . 30 based Networks . . . . . . . . . . . . . . . . . . . 31
8.1.8. Deterministic vs Best-Effort Traffic . . . . . . . . 30 8.1.8. Deterministic vs Best-Effort Traffic . . . . . . . . 31
8.1.9. Deterministic Flows . . . . . . . . . . . . . . . . . 31 8.1.9. Deterministic Flows . . . . . . . . . . . . . . . . . 32
8.1.10. Unused Reserved Bandwidth . . . . . . . . . . . . . . 31 8.1.10. Unused Reserved Bandwidth . . . . . . . . . . . . . . 32
8.1.11. Interoperability . . . . . . . . . . . . . . . . . . 31 8.1.11. Interoperability . . . . . . . . . . . . . . . . . . 32
8.1.12. Cost Reductions . . . . . . . . . . . . . . . . . . . 31 8.1.12. Cost Reductions . . . . . . . . . . . . . . . . . . . 32
8.1.13. Insufficiently Secure Devices . . . . . . . . . . . . 32 8.1.13. Insufficiently Secure Devices . . . . . . . . . . . . 33
8.1.14. DetNet Network Size . . . . . . . . . . . . . . . . . 32 8.1.14. DetNet Network Size . . . . . . . . . . . . . . . . . 33
8.1.15. Multiple Hops . . . . . . . . . . . . . . . . . . . . 33 8.1.15. Multiple Hops . . . . . . . . . . . . . . . . . . . . 34
8.1.16. Level of Service . . . . . . . . . . . . . . . . . . 33 8.1.16. Level of Service . . . . . . . . . . . . . . . . . . 34
8.1.17. Bounded Latency . . . . . . . . . . . . . . . . . . . 33 8.1.17. Bounded Latency . . . . . . . . . . . . . . . . . . . 34
8.1.18. Low Latency . . . . . . . . . . . . . . . . . . . . . 34 8.1.18. Low Latency . . . . . . . . . . . . . . . . . . . . . 35
8.1.19. Bounded Jitter (Latency Variation) . . . . . . . . . 34 8.1.19. Bounded Jitter (Latency Variation) . . . . . . . . . 35
8.1.20. Symmetrical Path Delays . . . . . . . . . . . . . . . 34 8.1.20. Symmetrical Path Delays . . . . . . . . . . . . . . . 35
8.1.21. Reliability and Availability . . . . . . . . . . . . 34 8.1.21. Reliability and Availability . . . . . . . . . . . . 35
8.1.22. Redundant Paths . . . . . . . . . . . . . . . . . . . 35 8.1.22. Redundant Paths . . . . . . . . . . . . . . . . . . . 36
8.1.23. Security Measures . . . . . . . . . . . . . . . . . . 35 8.1.23. Security Measures . . . . . . . . . . . . . . . . . . 36
8.2. Summary of Attack Types per Use Case Common Theme . . . . 35 8.2. Summary of Attack Types per Use Case Common Theme . . . . 36
8.3. Security Considerations for OAM Traffic . . . . . . . . . 38 8.3. Security Considerations for OAM Traffic . . . . . . . . . 39
9. DetNet Technology-Specific Threats . . . . . . . . . . . . . 38 9. DetNet Technology-Specific Threats . . . . . . . . . . . . . 39
9.1. IP . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 9.1. IP . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
9.2. MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . 40 9.2. MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . 41
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 41 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42
11. Security Considerations . . . . . . . . . . . . . . . . . . . 41 11. Security Considerations . . . . . . . . . . . . . . . . . . . 42
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 41 12. Privacy Considerations . . . . . . . . . . . . . . . . . . . 42
13. Informative References . . . . . . . . . . . . . . . . . . . 42 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 45 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 43
14.1. Normative References . . . . . . . . . . . . . . . . . . 43
14.2. Informative References . . . . . . . . . . . . . . . . . 44
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 47
1. Introduction 1. Introduction
A deterministic network is one that can carry data flows for real- A deterministic network is one that can carry data flows for real-
time applications with extremely low data loss rates and bounded time applications with extremely low data loss rates and bounded
latency. Deterministic networks have been successfully deployed in latency. Deterministic networks have been successfully deployed in
real-time Operational Technology (OT) applications for some years. real-time Operational Technology (OT) applications for some years.
However, such networks are typically isolated from external access, However, such networks are typically isolated from external access,
and thus the security threat from external attackers is low. IETF and thus the security threat from external attackers is low. IETF
Deterministic Networking (DetNet, [RFC8655]) specifies a set of Deterministic Networking (DetNet, [RFC8655]) specifies a set of
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IT Information Technology (the application of computers to IT Information Technology (the application of computers to
store, study, retrieve, transmit, and manipulate data or information, store, study, retrieve, transmit, and manipulate data or information,
often in the context of a business or other enterprise - [IT_DEF]). often in the context of a business or other enterprise - [IT_DEF]).
OT Operational Technology (the hardware and software OT Operational Technology (the hardware and software
dedicated to detecting or causing changes in physical processes dedicated to detecting or causing changes in physical processes
through direct monitoring and/or control of physical devices such as through direct monitoring and/or control of physical devices such as
valves, pumps, etc. - [OT_DEF]) valves, pumps, etc. - [OT_DEF])
MITM Man in the Middle
Component A component of a DetNet system - used here to refer Component A component of a DetNet system - used here to refer
to any hardware or software element of a DetNet network which to any hardware or software element of a DetNet network which
implements DetNet-specific functionality, for example all or part of implements DetNet-specific functionality, for example all or part of
a router, switch, or end system. a router, switch, or end system.
Resource Segmentation Used as a more general form for Network Resource Segmentation Used as a more general form for Network
Segmentation (the act or practice of splitting a computer network Segmentation (the act or practice of splitting a computer network
into subnetworks, each being a network segment - [RS_DEF]) into subnetworks, each being a network segment - [RS_DEF])
3. Security Considerations for DetNet Component Design 3. Security Considerations for DetNet Component Design
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A DetNet system security designer relies on the premise that any A DetNet system security designer relies on the premise that any
resources allocated to a resource-reserved (OT-type) flow are resources allocated to a resource-reserved (OT-type) flow are
inviolable, in other words there is no physical possibility within a inviolable, in other words there is no physical possibility within a
DetNet component that resources allocated to a given flow can be DetNet component that resources allocated to a given flow can be
compromised by any type of traffic in the network; this includes both compromised by any type of traffic in the network; this includes both
malicious traffic as well as inadvertent traffic such as might be malicious traffic as well as inadvertent traffic such as might be
produced by a malfunctioning component, for example one made by a produced by a malfunctioning component, for example one made by a
different manufacturer. From a security standpoint, this is a different manufacturer. From a security standpoint, this is a
critical assumption, for example when designing against DOS attacks. critical assumption, for example when designing against DOS attacks.
It is the responsibility of the component designer to ensure that It is the responsibility of the component designer to ensure that
this condition is met; this implies protection against excess traffic this condition is met; this implies protection against excess traffic
from adjacent flows, and against compromises to the resource from adjacent flows, and against compromises to the resource
allocation/deallocation process. allocation/deallocation process, for example through the use of
traffic shaping and policing.
As an example, consider the implementation of Flow Aggregation for
DetNet flows (as discussed in
[I-D.ietf-detnet-data-plane-framework]). In this example say there
are N flows that are to be aggregated, thus the bandwidth resources
of the aggregate flow must be sufficient to contain the sum of the
bandwidth reservation for the N flows. However if one of those flows
were to consume more than its individually allocated BW, this could
cause starvation of the other flows. Thus simply providing and
enforcing the calculated aggregate bandwidth may not be a complete
solution - the bandwidth for each individual flow must still be
guaranteed, for example via ingress policing of each flow (i.e.
before it is aggregated). Alternatively, if by some other means each
flow to be aggregated can be trusted not to exceed its allocated
bandwidth, the same goal can be achieved.
3.2. Explicit Routes 3.2. Explicit Routes
The DetNet-specific purpose for constraining the network's ability to The DetNet-specific purpose for constraining the network's ability to
re-route OT traffic is to maintain the specified service parameters re-route OT traffic is to maintain the specified service parameters
(such as upper and lower latency boundaries) for a given flow. For (such as upper and lower latency boundaries) for a given flow. For
example if the network were to re-route a flow (or some part of a example if the network were to re-route a flow (or some part of a
flow) based exclusively on statistical path usage metrics, or due to flow) based exclusively on statistical path usage metrics, or due to
malicious activity, it is possible that the new path would have a malicious activity, it is possible that the new path would have a
latency that is outside the required latency bounds which were latency that is outside the required latency bounds which were
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a degree which is implementation-dependent) through hitless redundant a degree which is implementation-dependent) through hitless redundant
packet delivery. (Note that PREOF is not defined for a DetNet IP packet delivery. (Note that PREOF is not defined for a DetNet IP
data plane). data plane).
It is the responsibility of the system designer to determine the It is the responsibility of the system designer to determine the
level of reliability required by their use case, and to specify level of reliability required by their use case, and to specify
redundant paths sufficient to provide the desired level of redundant paths sufficient to provide the desired level of
reliability (in as much as that reliability can be provided through reliability (in as much as that reliability can be provided through
the use of redundant paths). It is the responsibility of the the use of redundant paths). It is the responsibility of the
component designer to ensure that the relevant PREOF operations are component designer to ensure that the relevant PREOF operations are
executed reliably and securely. (However, note that not all PREOF executed reliably and securely, to avoid potentially catastrophic
operations are necessarily implemented in every network; for example situations for the operational technology relying on them.
a packet re-ordering function may not be necessary if the packets are
either not required to be in order, or if the ordering is performed
in some other part of the network.)
As noted in Section 7.2, Integrity Protection, there is a trust However, note that not all PREOF operations are necessarily
relationship between the pair of devices that replicate and remove implemented in every network; for example a packet re-ordering
packets, so it is the responsibility of the system designer to define function may not be necessary if the packets are either not required
these relationships with the appropriate security considerations, and to be in order, or if the ordering is performed in some other part of
the components must each uphold the security rights implied by these the network.
relationships.
Ideally a redundant path could be specified from end to end of the Ideally a redundant path could be specified from end to end of the
flow's path, however given that this is not always possible (as flow's path, however given that this is not always possible (as
described in [RFC8655]) the system designer will need to consider the described in [RFC8655]) the system designer will need to consider the
resulting end-to-end reliability and security resulting from any resulting end-to-end reliability and security resulting from any
given arrangment of network segments along the path, each of which given arrangment of network segments along the path, each of which
provides its individual PREOF implementation and thus its individual provides its individual PREOF implementation and thus its individual
level of reliabiilty and security. level of reliabiilty and security.
At the data plane the implementation of PREOF depends on the correct At the data plane the implementation of PREOF depends on the correct
assignment and interpretation of packet sequence numbers, as well as assignment and interpretation of packet sequence numbers, as well as
the actions taken based on them, such as elimination. Thus the the actions taken based on them, such as elimination (including
elimination of packets with spurious sequence numbers). Thus the
integrity of these values must be maintained by the component as they integrity of these values must be maintained by the component as they
are assigned by the DetNet Data Plane's Service sub-layer, and are assigned by the DetNet Data Plane's Service sub-layer, and
transported by the Forwarding sub-layer. transported by the Forwarding sub-layer. This is no different than
the integrity of the values in any header used by the DetNet (or any
other) data plane, and is not unique to redundant paths. From the
sequence number injection perspective, it is no different from any
other protocols that use sequence numbers.
3.4. Timing (or other) Violation Reporting 3.4. Timing (or other) Violation Reporting
Another fundamental assumption of a secure DetNet is that in any case Another fundamental assumption of a secure DetNet is that in any case
in which an incoming packet arrives with any timing or bandwidth in which an incoming packet arrives with any timing or bandwidth
violation, something can be done about it which doesn't cause damage violation, something can be done about it which doesn't cause damage
to the system. For example having the network shut down a link if a to the system. For example having the network shut down a link if a
packet arrives outside of its prescribed time window may serve the packet arrives outside of its prescribed time window may serve the
attacker better than it serves the network. That means that the attacker better than it serves the network. That means that the
component's data plane must be able to detect and act on a variety of component's data plane must be able to detect and act on a variety of
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as if it were entering the domain at an ingress node). The remarks as if it were entering the domain at an ingress node). The remarks
in [RFC2474] regarding IPsec and Tunnelling Interactions are also in [RFC2474] regarding IPsec and Tunnelling Interactions are also
relevant (though this is not to say that other sections are less relevant (though this is not to say that other sections are less
relevant). relevant).
5. Security Threats 5. Security Threats
This section presents a threat model, and analyzes the possible This section presents a threat model, and analyzes the possible
threats in a DetNet-enabled network. The threats considered in this threats in a DetNet-enabled network. The threats considered in this
section are independent of any specific technologies used to section are independent of any specific technologies used to
implement the DetNet; Section 9) considers attacks that are implement the DetNet; Section 9 considers attacks that are associated
associated with the DetNet technologies encompassed by with the DetNet technologies encompassed by
[I-D.ietf-detnet-data-plane-framework]. [I-D.ietf-detnet-data-plane-framework].
We distinguish controller plane threats from data plane threats. The We distinguish controller plane threats from data plane threats. The
attack surface may be the same, but the types of attacks as well as attack surface may be the same, but the types of attacks as well as
the motivation behind them, are different. For example, a delay the motivation behind them, are different. For example, a delay
attack is more relevant to data plane than to controller plane. attack is more relevant to data plane than to controller plane.
There is also a difference in terms of security solutions: the way There is also a difference in terms of security solutions: the way
you secure the data plane is often different than the way you secure you secure the data plane is often different than the way you secure
the controller plane. the controller plane.
5.1. Threat Model 5.1. Threat Model
The threat model used in this memo is based on the threat model of The threat model used in this memo employs organizational elements of
Section 3.1 of [RFC7384]. This model classifies attackers based on the threat models of [RFC7384] and [RFC7835] . This model classifies
two criteria: attackers based on two criteria:
o Internal vs. external: internal attackers either have access to a o Internal vs. external: internal attackers either have access to a
trusted segment of the network or possess the encryption or trusted segment of the network or possess the encryption or
authentication keys. External attackers, on the other hand, do authentication keys. External attackers, on the other hand, do
not have the keys and have access only to the encrypted or not have the keys and have access only to the encrypted or
authenticated traffic. authenticated traffic.
o Man in the Middle (MITM) vs. packet injector: MITM attackers are o On-path vs. off-path: on-path attackers are located in a position
located in a position that allows interception and modification of that allows interception and modification of in-flight protocol
in-flight protocol packets, whereas a traffic injector can only packets, whereas off-path attackers can only attack by generating
attack by generating protocol packets. protocol packets.
Care has also been taken to adhere to Section 5 of [RFC3552], both Care has also been taken to adhere to Section 5 of [RFC3552], both
with respect to which attacks are considered out-of-scope for this with respect to which attacks are considered out-of-scope for this
document, but also which are considered to be the most common threats document, but also which are considered to be the most common threats
(explored further in Section 5.2, Threat Analysis). Most of the (explored further in Section 5.2, Threat Analysis). Most of the
direct threats to DetNet are active attacks, but it is highly direct threats to DetNet are active attacks (i.e. attacks that modify
suggested that DetNet application developers take appropriate DetNet traffic), but it is highly suggested that DetNet application
measures to protect the content of the DetNet flows from passive developers take appropriate measures to protect the content of the
attacks. DetNet flows from passive attacks (i.e. attacks that observe but do
not modify DetNet traffic) for example through the use of TLS or
DTLS.
DetNet-Service, one of the service scenarios described in DetNet-Service, one of the service scenarios described in
[I-D.varga-detnet-service-model], is the case where a service [I-D.varga-detnet-service-model], is the case where a service
connects DetNet networking islands, i.e. two or more otherwise connects DetNet networking islands, i.e. two or more otherwise
independent DetNet network domains are connected via a link that is independent DetNet network domains are connected via a link that is
not intrinsically part of either network. This implies that there not intrinsically part of either network. This implies that there
could be DetNet traffic flowing over a non-DetNet link, which may could be DetNet traffic flowing over a non-DetNet link, which may
provide an attacker with an advantageous opportunity to tamper with provide an attacker with an advantageous opportunity to tamper with
DetNet traffic. The security properties of non-DetNet links are DetNet traffic. The security properties of non-DetNet links are
outside of the scope of DetNet Security, but it should be noted that outside of the scope of DetNet Security, but it should be noted that
skipping to change at page 13, line 5 skipping to change at page 13, line 24
every SN value S with a higher value S+C, where C is a constant every SN value S with a higher value S+C, where C is a constant
integer. Thus, the attacker creates a false illusion that the integer. Thus, the attacker creates a false illusion that the
attacked path has the lowest delay, causing all packets from other attacked path has the lowest delay, causing all packets from other
paths to be eliminated in favor of the attacked path. Once the paths to be eliminated in favor of the attacked path. Once the
flow from the compromised path is favored by the elminating flow from the compromised path is favored by the elminating
bridge, the flow is hijacked by the attacker. It is now posible bridge, the flow is hijacked by the attacker. It is now posible
to either replace en route packets with malicious packets, or to either replace en route packets with malicious packets, or
simply injecting errors, causing the packets to be dropped at simply injecting errors, causing the packets to be dropped at
their destination. their destination.
5.2.5. Path Choice o Amplification - an attacker who injects packets into a flow that
is to be replicated will have their attack amplified through the
replication process. This is no different than any attacker who
injects packets that are delivered through multicast, broadcast,
or other point-to-multi-point mechanisms.
5.2.5.1. Path Manipulation 5.2.5. Controller Plane
An attacker can maliciously change, add, or remove a path, thereby 5.2.5.1. Path Choice Manipulation
affecting the corresponding DetNet flows that use the path.
5.2.5.2. Path Choice: Increased Attack Surface 5.2.5.1.1. Control or Signaling Packet Modification
An attacker can maliciously modify en route control packets in order
to disrupt or manipulate the DetNet path/resource allocation.
5.2.5.1.2. Control or Signaling Packet Injection
An attacker can maliciously inject control packets in order to
disrupt or manipulate the DetNet path/resource allocation.
5.2.5.1.3. Increased Attack Surface
One of the possible consequences of a path manipulation attack is an One of the possible consequences of a path manipulation attack is an
increased attack surface. Thus, when the attack described in the increased attack surface. Thus, when the attack described in the
previous subsection is implemented, it may increase the potential of previous subsection is implemented, it may increase the potential of
other attacks to be performed. other attacks to be performed.
5.2.6. Controller Plane 5.2.5.2. Compromised Controller
5.2.6.1. Control or Signaling Packet Modification
An attacker can maliciously modify en route control packets in order
to disrupt or manipulate the DetNet path/resource allocation.
5.2.6.2. Control or Signaling Packet Injection An attacker can subvert a controller, or enable a compromised
controller to falsely represent itself as a controller so that the
network nodes believe it to be authorized to instruct them.
An attacker can maliciously inject control packets in order to Presence of compromised nodes in a DetNet is not a "new" threat that
disrupt or manipulate the DetNet path/resource allocation. arises as a result of determinism or time sensitivity; the same
techniques used to prevent or mitigate against compromised nodes in
any network are equally applicable in the DetNet case. However this
underscores the requirement for careful system security design in a
DetNet, given that the effects of even one bad actor on the network
can be potentially catastrophic.
5.2.7. Scheduling or Shaping Security concerns specific to any given controller plane technology
used in DetNet will be addressed by the DetNet documents associated
with that technology.
5.2.7.1. Reconnaissance 5.2.6. Reconnaissance
A passive eavesdropper can identify DetNet flows and then gather A passive eavesdropper can identify DetNet flows and then gather
information about en route DetNet flows, e.g., the number of DetNet information about en route DetNet flows, e.g., the number of DetNet
flows, their bandwidths, their schedules, or other temporal flows, their bandwidths, their schedules, or other temporal
properties. The gathered information can later be used to invoke properties. The gathered information can later be used to invoke
other attacks on some or all of the flows. other attacks on some or all of the flows.
Note that in some cases DetNet flows may be identified based on an Note that in some cases DetNet flows may be identified based on an
explicit DetNet header, but in some cases the flow identification may explicit DetNet header, but in some cases the flow identification may
be based on fields from the L3/L4 headers. If L3/L4 headers are be based on fields from the L3/L4 headers. If L3/L4 headers are
involved, for the purposes of this document we assume they are involved, for the purposes of this document we assume they are
encrypted and/or integrity-protected from external attackers. encrypted and/or integrity-protected from external attackers.
5.2.8. Time Synchronization Mechanisms 5.2.7. Time Synchronization Mechanisms
An attacker can use any of the attacks described in [RFC7384] to An attacker can use any of the attacks described in [RFC7384] to
attack the synchronization protocol, thus affecting the DetNet attack the synchronization protocol, thus affecting the DetNet
service. service.
5.3. Threat Summary 5.3. Threat Summary
A summary of the attacks that were discussed in this section is A summary of the attacks that were discussed in this section is
presented in Figure 1. For each attack, the table specifies the type presented in Figure 1. For each attack, the table specifies the type
of attackers that may invoke the attack. In the context of this of attackers that may invoke the attack. In the context of this
summary, the distinction between internal and external attacks is summary, the distinction between internal and external attacks is
under the assumption that a corresponding security mechanism is being under the assumption that a corresponding security mechanism is being
used, and that the corresponding network equipment takes part in this used, and that the corresponding network equipment takes part in this
mechanism. mechanism.
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
| Attack | Attacker Type | | Attack | Attacker Type |
| +---------+---------+ | +---------+---------+
| |Internal |External | | |Internal |External |
| |MITM|Inj.|MITM|Inj.| | |On-P|Off-P|On-P|Off-P|
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|Delay attack | + | + | + | + | |Delay attack | + | + | + | + |
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|DetNet Flow Modification or Spoofing | + | + | | | |DetNet Flow Modification or Spoofing | + | + | | |
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|Inter-segment Attack | + | + | | | |Inter-segment Attack | + | + | | |
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|Replication: Increased Attack Surface | + | + | + | + | |Replication: Increased Attack Surface | + | + | + | + |
+-----------------------------------------+----+----+----+----+ +-----------------------------------------+----+----+----+----+
|Replication-related Header Manipulation | + | | | | |Replication-related Header Manipulation | + | | | |
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typically use a subset of these tools, based on a system-specific typically use a subset of these tools, based on a system-specific
threat analysis. threat analysis.
7.1. Path Redundancy 7.1. Path Redundancy
Description Description
A DetNet flow that can be forwarded simultaneously over multiple A DetNet flow that can be forwarded simultaneously over multiple
paths. Path replication and elimination [RFC8655] provides paths. Path replication and elimination [RFC8655] provides
resiliency to dropped or delayed packets. This redundancy resiliency to dropped or delayed packets. This redundancy
improves the robustness to failures and to man-in-the-middle improves the robustness to failures and to on-path attacks. Note:
attacks. Note: At the time of this writing, PREOF is not defined At the time of this writing, PREOF is not defined for the IP data
for the IP data plane. plane.
Related attacks Related attacks
Path redundancy can be used to mitigate various man-in-the-middle Path redundancy can be used to mitigate various on-path attacks,
attacks, including attacks described in Section 5.2.1, including attacks described in Section 5.2.1, Section 5.2.2,
Section 5.2.2, Section 5.2.3, and Section 5.2.8. However it is Section 5.2.3, and Section 5.2.7. However it is also possible
also possible that multiple paths may make it more difficult to that multiple paths may make it more difficult to locate the
locate the source of a MITM attacker. source of an on-path attacker.
A delay modulation attack could result in extensively exercising A delay modulation attack could result in extensively exercising
parts of the code that wouldn't normally be extensively exercised parts of the code that wouldn't normally be extensively exercised
and thus might expose flaws in the system that might otherwise not and thus might expose flaws in the system that might otherwise not
be exposed. be exposed.
7.2. Integrity Protection 7.2. Integrity Protection
Description Description
An integrity protection mechanism, such as a hash-based Message
An integrity protection mechanism, such as a Hash-based Message Authentication Code (MAC) can be used to mitigate modification
Authentication Code (HMAC) can be used to mitigate modification attacks on IP packets. Such MAC usage needs to be part of a
attacks on IP packets. Integrity protection in the controller security association that is established and managed by a security
plane is discussed in Section 7.6. association protocol (such as IKEv2 for IPsec security
associations). Integrity protection in the controller plane is
discussed in Section 7.6.
Packet Sequence Number Integrity Considerations Packet Sequence Number Integrity Considerations
The use of PREOF in a DetNet implementation implies the use of a The use of PREOF in a DetNet implementation implies the use of a
sequence number for each packet. There is a trust relationship sequence number for each packet. There is a trust relationship
between the device that adds the sequence number and the device between the device that adds the sequence number and the device
that removes the sequence number. The sequence number may be end- that removes the sequence number. The sequence number may be end-
to-end source to destination, or may be added/deleted by network to-end source to destination, or may be added/deleted by network
edge devices. The adder and remover(s) have the trust edge devices. The adder and remover(s) have the trust
relationship because they are the ones that ensure that the relationship because they are the ones that ensure that the
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Related attacks Related attacks
Integrity protection mitigates attacks related to modification and Integrity protection mitigates attacks related to modification and
tampering, including the attacks described in Section 5.2.2 and tampering, including the attacks described in Section 5.2.2 and
Section 5.2.4. Section 5.2.4.
7.3. DetNet Node Authentication 7.3. DetNet Node Authentication
Description Description
Source authentication verifies the authenticity of DetNet sources, Authentication verifies the identity of DetNet nodes (including
enabling mitigation of spoofing attacks. Note that while DetNet Controller Plane nodes), enabling mitigation of spoofing
integrity protection (Section 7.2) prevents intermediate nodes attacks. Note that while integrity protection (Section 7.2)
from modifying information, authentication can provide traffic prevents intermediate nodes from modifying information,
origin verification, i.e. to verify that each packet in a DetNet authentication (such as provided by IPsec or MACsec) can provide
flow is from a trusted source. Authentication may be implemented traffic origin verification, i.e. to verify that each packet in a
as part of ingress filtering, for example. DetNet flow is from a trusted source.
Related attacks Related attacks
DetNet node authentication is used to mitigate attacks related to DetNet node authentication is used to mitigate attacks related to
spoofing, including the attacks of Section 5.2.2, and spoofing, including the attacks of Section 5.2.2, and
Section 5.2.4. Section 5.2.4.
7.4. Dummy Traffic Insertion 7.4. Dummy Traffic Insertion
Description Description
With some queueing methods such as [IEEE802.1Qch-2017] it is With some queueing methods such as [IEEE802.1Qch-2017] it is
possible to introduce dummy traffic in order to regularize the possible to introduce dummy traffic in order to regularize the
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Description Description
With some queueing methods such as [IEEE802.1Qch-2017] it is With some queueing methods such as [IEEE802.1Qch-2017] it is
possible to introduce dummy traffic in order to regularize the possible to introduce dummy traffic in order to regularize the
timing of packet transmission. timing of packet transmission.
Related attacks Related attacks
Removing distinctive temporal properties of individual packets or Removing distinctive temporal properties of individual packets or
flows can be used to mitigate against reconnaissance attacks flows can be used to mitigate against reconnaissance attacks
Section 5.2.7. Section 5.2.6.
7.5. Encryption 7.5. Encryption
Description Description
DetNet flows can in principle be forwarded in encrypted form at DetNet flows can in principle be forwarded in encrypted form at
the DetNet layer, however, regarding encryption of IP headers see the DetNet layer, however, regarding encryption of IP headers see
Section 9. Section 9.
DetNet nodes do not have any need to inspect the payload of any DetNet nodes do not have any need to inspect the payload of any
DetNet packets, making them data-agnostic. This means that end- DetNet packets, making them data-agnostic. This means that end-
to- end encryption at the application layer is an acceptable way to- end encryption at the application layer is an acceptable way
to protect user data. to protect user data.
Encryption can also be applied at the subnet layer, for example Encryption can also be applied at the subnet layer, for example
for Ethernet using MACSec, as noted in Section 9. for Ethernet using MACSec, as noted in Section 9.
Related attacks Related attacks
Encryption can be used to mitigate recon attacks (Section 5.2.7). Encryption can be used to mitigate recon attacks (Section 5.2.6).
However, for a DetNet network to give differentiated quality of However, for a DetNet network to give differentiated quality of
service on a flow-by-flow basis, the network must be able to service on a flow-by-flow basis, the network must be able to
identify the flows individually. This implies that in a recon identify the flows individually. This implies that in a recon
attack the attacker may also be able to track individual flows to attack the attacker may also be able to track individual flows to
learn more about the system. learn more about the system.
7.5.1. Encryption Considerations for DetNet 7.5.1. Encryption Considerations for DetNet
Any compute time which is required for encryption and decryption Any compute time which is required for encryption and decryption
processing ('crypto') must be included in the flow latency processing ('crypto') must be included in the flow latency
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7.6. Control and Signaling Message Protection 7.6. Control and Signaling Message Protection
Description Description
Control and sigaling messages can be protected using Control and sigaling messages can be protected using
authentication and integrity protection mechanisms. authentication and integrity protection mechanisms.
Related attacks Related attacks
These mechanisms can be used to mitigate various attacks on the These mechanisms can be used to mitigate various attacks on the
controller plane, as described in Section 5.2.6, Section 5.2.8 and controller plane, as described in Section 5.2.5, Section 5.2.7 and
Section 5.2.5. Section 5.2.5.1.
7.7. Dynamic Performance Analytics 7.7. Dynamic Performance Analytics
Description Description
The expectation is that the network will have a way to monitor to The expectation is that the network will have a way to monitor to
detect if timing guarantees are not being met, and a way to alert detect if timing guarantees are not being met, and a way to alert
the controller plane in that event. Information about the network the controller plane in that event. Information about the network
performance can be gathered in real-time in order to detect performance can be gathered in real-time in order to detect
anomalies and unusual behavior that may be the symptom of a anomalies and unusual behavior that may be the symptom of a
security attack. The gathered information can be based, for security attack. The gathered information can be based, for
example, on per-flow counters, bandwidth measurement, and example, on per-flow counters, bandwidth measurement, and
monitoring of packet arrival times. Unusual behavior or monitoring of packet arrival times. Unusual behavior or
potentially malicious nodes can be reported to a management potentially malicious nodes can be reported to a management
system, or can be used as a trigger for taking corrective actions. system, or can be used as a trigger for taking corrective actions.
The information can be tracked by DetNet end systems and transit The information can be tracked by DetNet end systems and transit
nodes, and exported to a management system, for example using nodes, and exported to a management system, for example using
YANG. YANG.
If the monitoring or reporting mechanism itself is attacked or
subverted, this can result in malfunction of the network. The
design of the monitoring system needs to take this into account
based on the specifics of the monitoring or reporting system being
considered.
Related attacks Related attacks
Performance analytics can be used to mitigate various attacks, Performance analytics can be used to mitigate various attacks,
including the ones described in Section 5.2.1 (Delay Attack), including the ones described in Section 5.2.1 (Delay Attack),
Section 5.2.3 (Resource Segmentation Attack), and Section 5.2.8 Section 5.2.3 (Resource Segmentation Attack), and Section 5.2.7
(Time Sync Attack). (Time Sync Attack).
For example, in the case of data plane delay attacks, one possible For example, in the case of data plane delay attacks, one possible
mitigation is to timestamp the data at the source, and timestamp mitigation is to timestamp the data at the source, and timestamp
it again at the destination, and if the resulting latency exceeds it again at the destination, and if the resulting latency exceeds
the promised bound, discard that data and warn the operator (and/ the promised bound, discard that data and warn the operator (and/
or enter a fail-safe mode). Note that DetNet specifies packet or enter a fail-safe mode). Note that DetNet specifies packet
sequence numbering, however it does not specify use of packet sequence numbering, however it does not specify use of packet
timestamps, although they may be used by the underlying transport timestamps, although they may be used by the underlying transport
(for example TSN) to provide the service. (for example TSN) to provide the service.
skipping to change at page 28, line 19 skipping to change at page 29, line 19
implemented to provide analogous protection. implemented to provide analogous protection.
8.1.2. Central Administration 8.1.2. Central Administration
A DetNet network can be controlled by a centralized network A DetNet network can be controlled by a centralized network
configuration and control system. Such a system may be in a single configuration and control system. Such a system may be in a single
central location, or it may be distributed across multiple control central location, or it may be distributed across multiple control
entities that function together as a unified control system for the entities that function together as a unified control system for the
network. network.
In this document we distinguish between attacks on the DetNet All attacks named in this document which are relevant to controller
Controller plane vs. Data Plane. But is an attack affecting plane packets (and the controller itself) are relevant to this theme,
controller plane packets synonymous with an attack on the controller including Path Manipulation, Path Choice, Control Packet Modification
plane itself? For the purposes of this document let us consider an or Injection, Reconaissance and Attacks on Time Sync Mechanisms.
attack on the control system itself to be out of scope, and consider
all attacks named in this document which are relevant to controller
plane packets to be relevant to this theme, including Path
Manipulation, Path Choice, Control Packet Modification or Injection,
Reconaissance and Attacks on Time Sync Mechanisms.
8.1.3. Hot Swap 8.1.3. Hot Swap
A DetNet network is not expected to be "plug and play" - it is A DetNet network is not expected to be "plug and play" - it is
expected that there is some centralized network configuration and expected that there is some centralized network configuration and
control system. However, the ability to "hot swap" components (e.g. control system. However, the ability to "hot swap" components (e.g.
due to malfunction) is similar enough to "plug and play" that this due to malfunction) is similar enough to "plug and play" that this
kind of behavior may be expected in DetNet networks, depending on the kind of behavior may be expected in DetNet networks, depending on the
implementation. implementation.
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Packets sent over DetNet are not to be dropped by the network due to Packets sent over DetNet are not to be dropped by the network due to
congestion. (Packets may however intentionally be dropped for congestion. (Packets may however intentionally be dropped for
intended reasons, e.g. per security measures). intended reasons, e.g. per security measures).
A data plane attack may force packets to be dropped, for example a A data plane attack may force packets to be dropped, for example a
"long" Delay or Replication/Elimination or Flow Modification attack. "long" Delay or Replication/Elimination or Flow Modification attack.
The same result might be obtained by a controller plane attack, e.g. The same result might be obtained by a controller plane attack, e.g.
Path Manipulation or Signaling Packet Modification. Path Manipulation or Signaling Packet Modification.
It may be that such attacks are limited to Internal MITM attackers, It may be that such attacks are limited to Internal on-path
but other possibilities should be considered. attackers, but other possibilities should be considered.
An attack may also cause packets that should not be delivered to be An attack may also cause packets that should not be delivered to be
delivered, such as by forcing packets from one (e.g. replicated) path delivered, such as by forcing packets from one (e.g. replicated) path
to be preferred over another path when they should not be to be preferred over another path when they should not be
(Replication attack), or by Flow Modification, or by Path Choice or (Replication attack), or by Flow Modification, or by Path Choice or
Packet Injection. A Time Sync attack could cause a system that was Packet Injection. A Time Sync attack could cause a system that was
expecting certain packets at certain times to accept unintended expecting certain packets at certain times to accept unintended
packets based on compromised system time or time windowing in the packets based on compromised system time or time windowing in the
scheduler. scheduler.
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provide redundant paths that can be seamlessly switched between, all provide redundant paths that can be seamlessly switched between, all
the while maintaining the required performance of that system. the while maintaining the required performance of that system.
Replication-related attacks are by definition applicable here. Replication-related attacks are by definition applicable here.
Controller plane attacks can also interfere with the configuration of Controller plane attacks can also interfere with the configuration of
redundant paths. redundant paths.
8.1.23. Security Measures 8.1.23. Security Measures
A DetNet network must be made secure against devices failures, A DetNet network must be made secure against devices failures,
attackers, misbehaving devices, and so on. Does the threat affect attackers, misbehaving component, and so on. If the security
such security measures themselves, e.g. by attacking SW designed to mechanisms protecting the DetNet are attacked or subverted, this can
protect against device failure? result in malfunction of the network. The design of the security
system itself needs to take this into account based on the specifics
This is TBD, thus there are no specific entries in the mapping table of the security system being considered. The general topic of
Figure 4, however that does not imply that there could be no relevant protection of security mechanisms is not unique to DetNet; it is
attacks. identical to the case of securing any security mechanism for any
network. The text of this document addresses these concerns to the
extent that they are relevant to DetNet.
8.2. Summary of Attack Types per Use Case Common Theme 8.2. Summary of Attack Types per Use Case Common Theme
The List of Attacks table Figure 4 lists the attacks of Section 5, The List of Attacks table Figure 4 lists the attacks of Section 5,
Security Threats, assigning a number to each type of attack. That Security Threats, assigning a number to each type of attack. That
number is then used as a short form identifier for the attack in number is then used as a short form identifier for the attack in
Figure 5, Mapping Between Themes and Attacks. Figure 5, Mapping Between Themes and Attacks.
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| | Attack | Section | | | Attack |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 1|Delay Attack | Section 3.2.1 | | 1 |Delay Attack |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 2|DetNet Flow Modification or Spoofing | Section 3.2.2 | | 2 |DetNet Flow Modification or Spoofing |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 3|Inter-Segment Attack | Section 3.2.3 | | 3 |Inter-Segment Attack |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 4|Replication: Increased attack surface | Section 3.2.4.1 | | 4 |Replication: Increased attack surface |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 5|Replication-related Header Manipulation | Section 3.2.4.2 | | 5 |Replication-related Header Manipulation |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 6|Path Manipulation | Section 3.2.5.1 | | 6 |Path Manipulation |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 7|Path Choice: Increased Attack Surface | Section 3.2.5.2 | | 7 |Path Choice: Increased Attack Surface |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 8|Control or Signaling Packet Modification| Section 3.2.6.1 | | 8 |Control or Signaling Packet Modification|
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
| 9|Control or Signaling Packet Injection | Section 3.2.6.2 | | 9 |Control or Signaling Packet Injection |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
|10|Reconnaissance | Section 3.2.7 | | 10 |Reconnaissance |
+--+----------------------------------------+----------------------+ +----+----------------------------------------+
|11|Attacks on Time Sync Mechanisms | Section 3.2.8 | | 11 |Attacks on Time Sync Mechanisms |
+--+----------------------------------------+----------------------+ +--+----------------------------------------+
Figure 4: List of Attacks Figure 4: List of Attacks
The Mapping Between Themes and Attacks table Figure 5 maps the use The Mapping Between Themes and Attacks table Figure 5 maps the use
case themes of [RFC8578] (as also enumerated in this document) to the case themes of [RFC8578] (as also enumerated in this document) to the
attacks of Figure 4. Each row specifies a theme, and the attacks attacks of Figure 4. Each row specifies a theme, and the attacks
relevant to this theme are marked with a '+'. relevant to this theme are marked with a '+'. The row items which
have no threats associated with them are included in the table for
completeness of the list of Use Case Common Themes, and do not have
DetNet-specific threats associated with them.
+----------------------------+--------------------------------+ +----------------------------+--------------------------------+
| Theme | Attack | | Theme | Attack |
| +--+--+--+--+--+--+--+--+--+--+--+ | +--+--+--+--+--+--+--+--+--+--+--+
| | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11| | | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Network Layer - AVB/TSN Eth.| +| +| +| +| +| +| +| +| +| +| +| |Network Layer - AVB/TSN Eth.| +| +| +| +| +| +| +| +| +| +| +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
|Central Administration | | | | | | +| +| +| +| +| +| |Central Administration | | | | | | +| +| +| +| +| +|
+----------------------------+--+--+--+--+--+--+--+--+--+--+--+ +----------------------------+--+--+--+--+--+--+--+--+--+--+--+
skipping to change at page 38, line 25 skipping to change at page 39, line 25
administration, presumably transparent to the customer. Security administration, presumably transparent to the customer. Security
considerations for such traffic are not DetNet-specific (apart considerations for such traffic are not DetNet-specific (apart
from such traffic being subject to the same DetNet-specific from such traffic being subject to the same DetNet-specific
security considerations as any other DetNet data flow) and are security considerations as any other DetNet data flow) and are
thus not covered in this document. thus not covered in this document.
o OAM traffic generated by the customer. From a DetNet security o OAM traffic generated by the customer. From a DetNet security
point of view, DetNet security considerations for such traffic are point of view, DetNet security considerations for such traffic are
exactly the same as for any other customer data flows. exactly the same as for any other customer data flows.
Thus OAM traffic presents no additional (i.e. OAM-specific) DetNet From the perspective of an attack, OAM traffic is indistinguishable
security considerations. from DetNet traffic and the network needs to be secure against
injection, removal, or modification of traffic of any kind, including
OAM traffic. A DetNet is sensitive to any form of packet injection,
removal or manipulation and in this respect DetNet OAM traffic is no
different. Techniques for securing a DetNet against these threats
have been discussed elsewhere in this document.
9. DetNet Technology-Specific Threats 9. DetNet Technology-Specific Threats
Section 5, Security Threats, described threats which are independent Section 5, Security Threats, described threats which are independent
of a DetNet implementation. This section considers threats of a DetNet implementation. This section considers threats
specifically related to the IP- and MPLS-specific aspects of DetNet specifically related to the IP- and MPLS-specific aspects of DetNet
implementations. implementations.
The primary security considerations for the data plane specifically The primary security considerations for the data plane specifically
are to maintain the integrity of the data and the delivery of the are to maintain the integrity of the data and the delivery of the
skipping to change at page 39, line 52 skipping to change at page 41, line 7
Another way to look at DetNet IP security is to consider it in the Another way to look at DetNet IP security is to consider it in the
light of VPN security; as an industry we have a lot of experience light of VPN security; as an industry we have a lot of experience
with VPNs running through networks with other VPNs, it is well known with VPNs running through networks with other VPNs, it is well known
how to secure the network for that. However for a DetNet we have the how to secure the network for that. However for a DetNet we have the
additional subtlety that any possible interaction of one packet with additional subtlety that any possible interaction of one packet with
another can have a potentially deleterious effect on the time another can have a potentially deleterious effect on the time
properties of the flows. So the network must provide sufficient properties of the flows. So the network must provide sufficient
isolation between flows, for example by protecting the forwarding isolation between flows, for example by protecting the forwarding
bandwidth and related resources so that they are available to detnet bandwidth and related resources so that they are available to detnet
traffic, by whatever means are appropriate for that network's data traffic, by whatever means are appropriate for that network's data
plane. plane, for example through the use of queueing mechanisms.
In a VPN, bandwidth is generally guaranteed over a period of time, In a VPN, bandwidth is generally guaranteed over a period of time,
whereas in DetNet it is not aggregated over time. This implies that whereas in DetNet it is not aggregated over time. This implies that
any VPN-type protection mechanism must also maintain the DetNet any VPN-type protection mechanism must also maintain the DetNet
timing constraints. timing constraints.
9.2. MPLS 9.2. MPLS
An MPLS network carrying DetNet traffic is expected to be a "well- An MPLS network carrying DetNet traffic is expected to be a "well-
managed" network. Given that this is the case, it is difficult for managed" network. Given that this is the case, it is difficult for
skipping to change at page 41, line 6 skipping to change at page 42, line 9
which are NTP [RFC5905] and Precision Time Protocol [IEEE1588]. The which are NTP [RFC5905] and Precision Time Protocol [IEEE1588]. The
security requirements for these are described in [RFC7384]. security requirements for these are described in [RFC7384].
One particular problem that has been observed in operational tests of One particular problem that has been observed in operational tests of
TWTT protocols is the ability for two closely but not completely TWTT protocols is the ability for two closely but not completely
synchronized flows to beat and cause a sudden phase hit to one of the synchronized flows to beat and cause a sudden phase hit to one of the
flows. This can be mitigated by the careful use of a scheduling flows. This can be mitigated by the careful use of a scheduling
system in the underlying packet transport. system in the underlying packet transport.
Further consideration of protection against dynamic attacks is work Further consideration of protection against dynamic attacks is work
in progress. in progress. New work on MPLS security may also be applicable, for
example [I-D.ietf-mpls-opportunistic-encrypt].
10. IANA Considerations 10. IANA Considerations
This memo includes no requests from IANA. This memo includes no requests from IANA.
11. Security Considerations 11. Security Considerations
The security considerations of DetNet networks are presented The security considerations of DetNet networks are presented
throughout this document. throughout this document.
12. Contributors 12. Privacy Considerations
Privacy in the context of DetNet is maintained by the base
technologies specific to the DetNet and user traffic. For example
TSN can use MACsec, IP can use IPsec, applications can use IP
transport protocol-provided methods e.g. TLS and DTLS. MPLS
typically uses L2/L3 VPNs combined with the previously mentioned
privacy methods.
13. Contributors
The Editor would like to recognize the contributions of the following The Editor would like to recognize the contributions of the following
individuals to this draft. individuals to this draft.
Andrew J. Hacker (MistIQ Technologies, Inc)
Harrisburg, PA, USA
email ajhacker@mistiqtech.com,
web http://www.mistiqtech.com
Subir Das (Applied Communication Sciences) Subir Das (Applied Communication Sciences)
150 Mount Airy Road, Basking Ridge 150 Mount Airy Road, Basking Ridge
New Jersey, 07920, USA New Jersey, 07920, USA
email sdas@appcomsci.com email sdas@appcomsci.com
John Dowdell (Airbus Defence and Space) John Dowdell (Airbus Defence and Space)
Celtic Springs, Newport, NP10 8FZ, United Kingdom Celtic Springs, Newport, NP10 8FZ, United Kingdom
email john.dowdell.ietf@gmail.com email john.dowdell.ietf@gmail.com
Henrik Austad (SINTEF Digital) Henrik Austad (SINTEF Digital)
skipping to change at page 42, line 37 skipping to change at page 43, line 32
Futurewei Technologies Futurewei Technologies
email: stewart.bryant@gmail.com email: stewart.bryant@gmail.com
David Black David Black
Dell EMC Dell EMC
176 South Street, Hopkinton, MA 01748, USA 176 South Street, Hopkinton, MA 01748, USA
email: david.black@dell.com email: david.black@dell.com
Carsten Bormann Carsten Bormann
13. Informative References 14. References
14.1. Normative References
[I-D.ietf-detnet-ip]
Varga, B., Farkas, J., Berger, L., Fedyk, D., and S.
Bryant, "DetNet Data Plane: IP", draft-ietf-detnet-ip-07
(work in progress), July 2020.
[I-D.ietf-detnet-mpls]
Varga, B., Farkas, J., Berger, L., Malis, A., Bryant, S.,
and J. Korhonen, "DetNet Data Plane: MPLS", draft-ietf-
detnet-mpls-12 (work in progress), September 2020.
[RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas,
"Deterministic Networking Architecture", RFC 8655,
DOI 10.17487/RFC8655, October 2019,
<https://www.rfc-editor.org/info/rfc8655>.
14.2. Informative References
[ARINC664P7] [ARINC664P7]
ARINC, "ARINC 664 Aircraft Data Network, Part 7, Avionics ARINC, "ARINC 664 Aircraft Data Network, Part 7, Avionics
Full-Duplex Switched Ethernet Network", 2009. Full-Duplex Switched Ethernet Network", 2009.
[I-D.ietf-detnet-data-plane-framework] [I-D.ietf-detnet-data-plane-framework]
Varga, B., Farkas, J., Berger, L., Malis, A., and S. Varga, B., Farkas, J., Berger, L., Malis, A., and S.
Bryant, "DetNet Data Plane Framework", draft-ietf-detnet- Bryant, "DetNet Data Plane Framework", draft-ietf-detnet-
data-plane-framework-06 (work in progress), May 2020. data-plane-framework-06 (work in progress), May 2020.
[I-D.ietf-detnet-flow-information-model] [I-D.ietf-detnet-flow-information-model]
Varga, B., Farkas, J., Cummings, R., Jiang, Y., and D. Varga, B., Farkas, J., Cummings, R., Jiang, Y., and D.
Fedyk, "DetNet Flow Information Model", draft-ietf-detnet- Fedyk, "DetNet Flow Information Model", draft-ietf-detnet-
flow-information-model-10 (work in progress), May 2020. flow-information-model-10 (work in progress), May 2020.
[I-D.ietf-detnet-ip]
Varga, B., Farkas, J., Berger, L., Fedyk, D., and S.
Bryant, "DetNet Data Plane: IP", draft-ietf-detnet-ip-07
(work in progress), July 2020.
[I-D.ietf-detnet-ip-over-tsn] [I-D.ietf-detnet-ip-over-tsn]
Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet Varga, B., Farkas, J., Malis, A., and S. Bryant, "DetNet
Data Plane: IP over IEEE 802.1 Time Sensitive Networking Data Plane: IP over IEEE 802.1 Time Sensitive Networking
(TSN)", draft-ietf-detnet-ip-over-tsn-03 (work in (TSN)", draft-ietf-detnet-ip-over-tsn-03 (work in
progress), June 2020. progress), June 2020.
[I-D.ietf-detnet-mpls] [I-D.ietf-mpls-opportunistic-encrypt]
Varga, B., Farkas, J., Berger, L., Malis, A., Bryant, S., Farrel, A. and S. Farrell, "Opportunistic Security in MPLS
and J. Korhonen, "DetNet Data Plane: MPLS", draft-ietf- Networks", draft-ietf-mpls-opportunistic-encrypt-03 (work
detnet-mpls-10 (work in progress), July 2020. in progress), March 2017.
[I-D.varga-detnet-service-model] [I-D.varga-detnet-service-model]
Varga, B. and J. Farkas, "DetNet Service Model", draft- Varga, B. and J. Farkas, "DetNet Service Model", draft-
varga-detnet-service-model-02 (work in progress), May varga-detnet-service-model-02 (work in progress), May
2017. 2017.
[IEEE1588] [IEEE1588]
IEEE, "IEEE 1588 Standard for a Precision Clock IEEE, "IEEE 1588 Standard for a Precision Clock
Synchronization Protocol for Networked Measurement and Synchronization Protocol for Networked Measurement and
Control Systems Version 2", 2008. Control Systems Version 2", 2008.
skipping to change at page 45, line 29 skipping to change at page 46, line 38
[RFC6941] Fang, L., Ed., Niven-Jenkins, B., Ed., Mansfield, S., Ed., [RFC6941] Fang, L., Ed., Niven-Jenkins, B., Ed., Mansfield, S., Ed.,
and R. Graveman, Ed., "MPLS Transport Profile (MPLS-TP) and R. Graveman, Ed., "MPLS Transport Profile (MPLS-TP)
Security Framework", RFC 6941, DOI 10.17487/RFC6941, April Security Framework", RFC 6941, DOI 10.17487/RFC6941, April
2013, <https://www.rfc-editor.org/info/rfc6941>. 2013, <https://www.rfc-editor.org/info/rfc6941>.
[RFC7384] Mizrahi, T., "Security Requirements of Time Protocols in [RFC7384] Mizrahi, T., "Security Requirements of Time Protocols in
Packet Switched Networks", RFC 7384, DOI 10.17487/RFC7384, Packet Switched Networks", RFC 7384, DOI 10.17487/RFC7384,
October 2014, <https://www.rfc-editor.org/info/rfc7384>. October 2014, <https://www.rfc-editor.org/info/rfc7384>.
[RFC7835] Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID
Separation Protocol (LISP) Threat Analysis", RFC 7835,
DOI 10.17487/RFC7835, April 2016,
<https://www.rfc-editor.org/info/rfc7835>.
[RFC8578] Grossman, E., Ed., "Deterministic Networking Use Cases", [RFC8578] Grossman, E., Ed., "Deterministic Networking Use Cases",
RFC 8578, DOI 10.17487/RFC8578, May 2019, RFC 8578, DOI 10.17487/RFC8578, May 2019,
<https://www.rfc-editor.org/info/rfc8578>. <https://www.rfc-editor.org/info/rfc8578>.
[RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas,
"Deterministic Networking Architecture", RFC 8655,
DOI 10.17487/RFC8655, October 2019,
<https://www.rfc-editor.org/info/rfc8655>.
[RS_DEF] Wikipedia, "RS Definition", 2020, [RS_DEF] Wikipedia, "RS Definition", 2020,
<https://en.wikipedia.org/wiki/Network_segmentation>. <https://en.wikipedia.org/wiki/Network_segmentation>.
Authors' Addresses Authors' Addresses
Tal Mizrahi
Huawei Network.IO Innovation Lab
Email: tal.mizrahi.phd@gmail.com
Ethan Grossman (editor) Ethan Grossman (editor)
Dolby Laboratories, Inc. Dolby Laboratories, Inc.
1275 Market Street 1275 Market Street
San Francisco, CA 94103 San Francisco, CA 94103
USA USA
Phone: +1 415 645 4726 Phone: +1 415 465 4339
Email: ethan.grossman@dolby.com Email: ethan@ieee.org
URI: http://www.dolby.com URI: http://www.dolby.com
Tal Mizrahi
Huawei Network.IO Innovation Lab
Email: tal.mizrahi.phd@gmail.com
Andrew J. Hacker
MistIQ Technologies, Inc
Harrisburg, PA
USA
Email: ajhacker@mistiqtech.com
URI: http://www.mistiqtech.com
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