Free DISA STIG and SRG Library | Vaulted

V-30736

The administrator must ensure the 6-to-4 router is configured to drop any outbound IPv6 packets from the internal network with a source address that is not within the 6to4 prefix 2002:V4ADDR::/48 where V4ADDR is the designated IPv4 6to4 address for the enclave.

Finding ID
NET-IPV6-066
Rule ID
SV-40541r1_rule
Severity
Cat III
CCE
(None)
Group Title
6-to-4 router not filtering invalid source address
CCI
(None)
Target Key
(None)
Documentable
No
Discussion

An automatic 6to4 tunnel allows isolated IPv6 domains to be connected over an IPv4 network and allows connections to remote IPv6 networks. The key difference between this deployment and manually configured tunnels is that the routers are not configured in pairs and thus do not require manual configuration because they treat the IPv4 infrastructure as a virtual non-broadcast link, using an IPv4 address embedded in the IPv6 address to find the remote end of the tunnel. In other words, the tunnel destination is determined by the IPv4 address of the external interface of the 6to4 router that is concatenated to the 2002::/16 prefix in the format 2002: V4ADDR::/48. Hence, the imbedded V4ADDR of the 6to4 prefix must belong to the same ipv4 prefix as configured on the external-facing interface of the 6to4 router.

Fix Text

If the router is functioning as a 6to4 router, configure an egress filter (inbound on the internal-facing interface) to drop any outbound IPv6 packets from the internal network with a source address that is not within the 6to4 prefix 2002:V4ADDR::/48 where V4ADDR is the designated IPv4 6to4 address for the enclave.

Check Content

Currently JUNOS does not support 6to4 automatic tunneling so this vulnerability is not applicable

Responsibility

Information Assurance Officer