V-283911

Discussion

A rogue router could send a fictitious routing update to convince a site's perimeter router to send traffic to an incorrect or rogue destination. This diverted traffic could be analyzed to learn confidential information about the site's network or used to disrupt the network's ability to communicate with other networks. This is known as a "traffic attraction attack" and is prevented by configuring neighbor router authentication for routing updates. However, using clear-text authentication provides little benefit because an attacker can intercept traffic and view the authentication key. This would allow the attacker to use the authentication key in an attack. Because MD5 is vulnerable to "birthday" attacks and may be compromised, routing protocol authentication must use FIPS 198-1-validated algorithms and modules to encrypt the authentication key. This requirement applies to all IPv4 and IPv6 protocols that are used to exchange routing or packet forwarding information. This includes all Interior Gateway Protocols, such as Open Shortest Path First (OSPF), Enhanced Interior Gateway Routing Protocol (EIGRP), and Intermediate System to Intermediate System (IS-IS). It also includes Exterior Gateway Protocols, such as Border Gateway Protocol (BGP); Multiprotocol Label Switching (MPLS)-related protocols, such as Label Distribution Protocol (LDP); and multicast-related protocols.

Check Content

Review the router configuration to verify it is using a NIST-validated FIPS 198-1 message authentication code algorithm to authenticate routing protocol messages.

Use the command below and verify "Algorithm" configured for each keychain is a NIST-validated algorithm:

- show system security keychain "test" detail

Key chain:test

Description                : (Not Specified)
TCP-Option number send     : tcp-ao                 Admin state   : Up
TCP-Option number receive  : tcp-ao                 Oper state    : Up
Used by                    : BGP
Expired                    : No

Key entries for key chain: test

Id               : 1                    Direction        : send-receive
Algorithm        : aes-128-cmac-96      Option           : none
Admin State      : Up                   RX Valid         : Yes
TX Active        : Yes                  Tolerance        : 300
Begin Time       : 2025/12/28 00:00:00  Begin Time (UTC) : 2025/12/28 00:00:00
End Time         : 2026/06/28 00:00:00  End Time (UTC)   : 2026/06/28 00:00:00

If a NIST-validated FIPS 198-1 message authentication code algorithm is not being used to authenticate routing protocol messages, this is a finding.