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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-96511	CISC-RT-000050	SV-105649r1_rule		Medium

Description
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.

Description

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.

STIG	Date
Cisco IOS Router RTR Security Technical Implementation Guide	2020-06-30

Details

Check Text ( C-95347r2_chk )
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.

Check Text ( C-95347r2_chk )

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.

Fix Text (F-102187r1_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

Fix Text (F-102187r1_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