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4. Security Considerations

This section is modeled after the template described in Section 3.7 of [YANG-GUIDE].

The "ietf-isis-sr-mpls" YANG module defines a data model that is designed to be accessed via YANG-based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. These YANG-based management protocols (1) have to use a secure transport layer (e.g., SSH [RFC4252], TLS [RFC8446], and QUIC [RFC9000]) and (2) have to use mutual authentication.

The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.

Writable Data Nodes​

There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., "config true", which is the default). All writable data nodes are likely to be sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) and delete operations to these data nodes without proper protection or authentication can have a negative effect on network operations. The following subtrees and data nodes have particular sensitivities/vulnerabilities:

  • /isis:isis/segment-routing
  • /isis:isis/protocol-srgb
  • /isis:isis/isis:interfaces/isis:interface/segment-routing
  • /isis:isis/isis:interfaces/isis:interface/isis:fast-reroute/ti-lfa

The ability to disable or enable IS-IS SR support and/or change SR configurations can result in a Denial-of-Service (DoS) attack, as this may cause traffic to be dropped or misrouted. Please refer to Section 5 of [RFC8667] for more information on SR extensions.

Readable Data Nodes​

Some of the readable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. Specifically, the following subtrees and data nodes have particular sensitivities/vulnerabilities:

  • /isis:router-capabilities/sr-capability
  • /isis:router-capabilities/sr-algorithms
  • /isis:router-capabilities/local-blocks
  • /isis:router-capabilities/srms-preference
  • and the augmentations to the IS-IS LSDB.

Unauthorized access to any data node of these subtrees can disclose the operational state information of the IS-IS protocol on a device.

There are no particularly sensitive RPC or action operations.

5. IANA Considerations

The IANA has assigned one new URI in the "IETF XML Registry" [RFC3688]:

URI:  urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls
Registrant Contact:  The IESG.
XML:  N/A; the requested URI is an XML namespace

This document also registers one new YANG module name in the "YANG Module Names" registry [RFC6020]:

Name:  ietf-isis-sr-mpls
Maintained by IANA?  N
Namespace:  urn:ietf:params:xml:ns:yang:ietf-isis-sr-mpls
Prefix:  isis-sr-mpls
Reference:  RFC 9902

6. References

6.1. Normative References​

6.2. Informative References​

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