AMLS-L3-000250 - Arista MLS must encrypt all methods of configured authentication for the OSPF routing protocol.

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 merely 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. 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 not performed this check. Please review the benchmark to ensure target compliance.

Solution

Configure routing protocol authentication to encrypt the authentication key via the following commands under the interface configuration mode. SHA1 must be used instead of MD5 in all cases when that option is available.

ip ospf authentication message-digest
ip ospf message-digest-key [number] md5 [type] [key]

For IPv6 global configuration, enter:
ipv6 router ospf [process number]
area [area number] authentication ipsec spi [spi number] [md5/sha1] [passphrase/key] [0/7] [passphrase/key]

Alternatively, under the interface configuration mode, enter:
ipv6 ospf authentication ipsec spi [spi number] [md5/sha1] [passphrase/key] [0/7] [passphrase/key]

To use ESP encryption on AH headers, instead enter:
ipv6 router ospf [process number]
area [area number] encryption ipsec spi [spi number] esp null [md5/sha1] [passphrase/key] [0/7] [passphrase/key]

or on an interface:
ipv6 ospf encryption ipsec spi [spi number] esp null [md5/sha1] [passphrase/key] [0/7] [passphrase/key]

See Also

http://iasecontent.disa.mil/stigs/zip/Apr2016/U_Arista_MLS_DCS-7000_Series_RTR_V1R2_STIG.zip

Item Details

References: CAT|II, CCI|CCI-000803, Group-ID|V-60919, Rule-ID|SV-75377r2_rule, STIG-ID|AMLS-L3-000250

Plugin: Arista

Control ID: f35c4ff57e83b7bb7c5bcf6fa15b25e70ddc796a0e99994908615092e4616699