Title

The Juniper PE router providing MPLS Layer 2 Virtual Private Network (L2VPN) services must be configured to authenticate targeted Label Distribution Protocol (LDP) sessions used to exchange virtual circuit (VC) information using a FIPS-approved message authentication code algorithm. (Cat II impact)

Discussion

LDP provides the signaling required for setting up and tearing down pseudowires (virtual circuits used to transport Layer 2 frames) across an MPLS IP core network. Using a targeted LDP session, each PE router advertises a virtual circuit label mapping that is used as part of the label stack imposed on the frames by the ingress PE router during packet forwarding. Authentication provides protection against spoofed TCP segments that can be introduced into the LDP sessions.

Check Content

Review the router configuration to determine if LDP messages are being authenticated for the targeted LDP sessions. In the example below, the PE router is LDP peering with remote PE 8.8.8.8. ldp { interface ge-0/1/0.0; interface ge-0/1/1.0; session 8.8.8.8 { authentication-algorithm hmac-sha-1-96; authentication-key-chain LDP_KEY; } } If authentication is not being used for the LDP targeted sessions using a FIPS-approved message authentication code algorithm, this is a finding.

Fix Text

Implement authentication for all targeted LDP sessions using a FIPS-approved message authentication code algorithm. [edit security authentication-key-chains] set key-chain LDP_KEY key 1 start-time 2018-05-01.12:00 secret xxxxxxxxxxxxx set key-chain LDP_KEY key 2 start-time 2018-09-01.12:00 secret xxxxxxxxxxxxx set key-chain LDP_KEY key 3 start-time 2019-01-01.12:00 secret xxxxxxxxxxxxx [edit protocols ldp] set session 8.8.8.8 authentication-algorithm hmac-sha-1-96 authentication-key-chain LDP_KEY

Additional Identifiers

Rule ID: SV-217070r878055_rule

Vulnerability ID: V-217070

Group Title: SRG-NET-000343-RTR-000001

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.