CISC-RT-000040 - The Cisco switch must be configured to use encryption for routing protocol authentication.

Information

A rogue switch could send a fictitious routing update to convince a site's perimeter switch 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 switch 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.

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.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Configure all routing protocol authentications to encrypt the authentication key.

EIGRP example:

SW2(config)#int g0/1
SW2(config-if)#ip authentication mode eigrp 1 md5
SW2(config-if)#ip authentication key-chain eigrp 1 EIGRP_KEY_CHAIN

OSPF example:

SW1(config)#key chain OSPF_KEY_CHAIN
SW1(config-keychain)#key 1
SW1(config-keychain-key)#key-string xxxxxx
SW1(config-keychain-key)#cryptographic-algorithm hmac-sha-256
SW1(config-keychain-key)#exit
SW1(config-keychain-key)#end
SW1(config)#interface GigabitEthernet0/2
SW1(config-if)#ip ospf authentication key-chain OSPF_KEY_CHAIN

RIP example:

SW2(config)#int g1/0
SW2(config-if)#ip rip authentication mode md5
SW2(config-if)#ip rip authentication key-chain RIP_KEY_CHAIN

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_IOS_Switch_Y23M07_STIG.zip

Item Details

References: CAT|II, CCI|CCI-000803, Rule-ID|SV-220422r892498_rule, STIG-ID|CISC-RT-000040, STIG-Legacy|SV-110691, STIG-Legacy|V-101587, Vuln-ID|V-220422

Plugin: Cisco

Control ID: 7ce4ee661802204761d7fd449e4c76f5417582ad367b8e17254c9e481d02ea6f