The Cisco switch must be configured to use encryption for routing protocol authentication.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| V-220422 | CISC-RT-000040 | SV-220422r892498_rule | Medium |
| Description |
|---|
| 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. |
| STIG | Date |
|---|---|
| Cisco IOS Switch RTR Security Technical Implementation Guide | 2023-02-17 |
Details
| Check Text ( C-22137r892498_chk ) |
|---|
| Review the switch configuration. For every routing protocol that affects the routing or forwarding tables, verify that the switch is encrypting the authentication key as shown in the examples below: EIGRP example: interface GigabitEthernet1/0 no switchport ip address x.x.x.x 255.255.255.0 ip authentication mode eigrp 1 md5 ip authentication key-chain eigrp 1 EIGRP_KEY_CHAIN OSPF Example: key chain OSPF_KEY_CHAIN key 1 key-string xxxxxxx cryptographic-algorithm hmac-sha-256 … … … interface GigabitEthernet0/1 ip address x.x.x.x 255.255.255.0 ip ospf authentication key-chain OSPF_KEY_CHAIN RIP example: interface GigabitEthernet1/0 no switchport ip rip authentication mode md5 ip rip authentication key-chain RIP_KEY_CHAIN If the routing protocol is not encrypting the authentication key, this is a finding. |
| Fix Text (F-22126r892366_fix) |
|---|
| 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 |