CISC-RT-000050 - The Cisco router must be configured to authenticate all routing protocol messages using NIST-validated FIPS 198-1 message authentication code algorithm.

Information

A rogue router could send a fictitious routing update to convince a site's perimeter router to send traffic to an incorrect or even a 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 since an attacker can intercept traffic and view the authentication key. This would allow the attacker to use the authentication key in an attack.

Since MD5 is vulnerable to 'birthday' attacks and may be compromised, routing protocol authentication must use FIPS 140-2 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 OSPF, EIGRP, and IS-IS) and Exterior Gateway Protocols (such as BGP), MPLS-related protocols (such as LDP), and multicast-related protocols.

Solution

Configure routing protocol authentication to use a NIST-validated FIPS 198-1 message authentication code algorithm as shown in the example.

RP/0/0/CPU0:R2(config)#key chain BGP_KEY_CHAIN
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN)#key 1
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-1)#accept-lifetime 01:00:00 jan 01 2019 01:00:00 april 01 2019
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-1)#key-string password xxxxxxxxxxx
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-1)#send-lifetime 01:00:00 jan 01 2019 01:00:00 april 01 2019
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-1)#cryptographic-algorithm hmac-sha1-12
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-1)#key 2
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-2)#accept-lifetime 01:00:00 april 01 2019 01:00:00 july 01 2019
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-2)#key-string password xxxxxxxxxxxxxxxx
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-2)#send-lifetime 01:00:00 april 01 2019 01:00:00 july 01 2019
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-2)#cryptographic-algorithm hmac-sha1-12
RP/0/0/CPU0:R2(config-OSPF_KEY_CHAIN-2)#end

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_IOS-XR_Router_Y21M04_STIG.zip

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-7, CAT|II, CCI|CCI-000803, Rule-ID|SV-216739r531087_rule, STIG-ID|CISC-RT-000050, STIG-Legacy|SV-105823, STIG-Legacy|V-96685, Vuln-ID|V-216739

Plugin: Cisco

Control ID: 973f2a8a9ef4b3fe8a00f0d72f9e9f531ef38d6debdd0f364765cf185b1b2090