Cisco IOS XE Router RTR STIG Version Comparison
Cisco IOS XE Router RTR Security Technical Implementation Guide
Comparison
There are 1 differences between versions v2 r2 (April 23, 2021) (the "left" version) and v2 r4 (April 27, 2022) (the "right" version).
Check CISC-RT-000050 was changed between these two versions. Green, underlined text was added, red, struck-out text was removed.
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Text Differences
Title
The Cisco router must be configured to authenticate all routing protocol messages using NIST-validated FIPS 198-1 message authentication code algorithm.
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. OSPF Example: key chain OSPF_KEY_CHAIN key 1 key-string xxxxxxx send-lifetime 00:00:00 Jan 1 2018 23:59:59 Mar 31 2018 accept-lifetime 00:00:00 Jan 1 2018 01:05:00 Apr 1 2018 cryptographic-algorithm hmac-sha-256 key 2 key-string yyyyyyy send-lifetime 00:00:00 Apr 1 2018 23:59:59 Jun 30 2018 accept-lifetime 23:55:00 Mar 31 2018 01:05:00 Jul 1 2018 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 If a NIST-validated FIPS 198-1 message authentication code algorithm is not being used to authenticate routing protocol messages, this is a finding. finding. NOTE: BGP protocol is Not Applicable to this requirement, as it can only support MD5 by design.
Discussion
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) IS-IS), and Exterior Gateway Protocols (such as BGP), MPLS-related protocols (such as LDP), and multicast-related protocols.
Fix
Configure routing protocol authentication to use a NIST-validated FIPS 198-1 message authentication code algorithm as shown in the example. R5(config)#key chain OSPF_KEY_CHAIN R5(config-keychain)#key 1 R5(config-keychain-key)#key-string xxxxxx R5(config-keychain-key)#send-lifetime 00:00:00 Jan 1 2018 23:59:59 Mar 31 2018 R5(config-keychain-key)#accept-lifetime 00:00:00 Jan 1 2018 01:05:00 Apr 1 2018 R5(config-keychain-key)#cryptographic-algorithm hmac-sha-256 R5(config-keychain-key)#exit R5(config-keychain)#key 2 R5(config-keychain-key)#key-string yyyyyyy R5(config-keychain-key)#send-lifetime 00:00:00 Apr 1 2018 23:59:59 Jun 30 2018 R5(config-keychain-key)#accept-lifetime 23:55:00 Mar 31 2018 01:05:00 Jul 1 2018 R5(config-keychain-key)#cryptographic-algorithm hmac-sha-256 R5(config-keychain-key)#end R5(config)#interface GigabitEthernet0/2 R5(config-if)#ip ospf authentication key-chain OSPF_KEY_CHAIN