Title

The system must prevent local applications from generating source-routed packets. (Cat II impact)

Discussion

Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures.

Check Content

Check the system for an IPF rule blocking outgoing source-routed packets. Procedure: # ipfstat -o Examine the list for rules such as: block out log quick all with opt lsrr block out log quick all with opt ssrr If the listed rules do not block both lsrr and ssrr options, this is a finding.

Fix Text

Edit /etc/ipf/ipf.conf and add rules to block outgoing source-routed packets, such as: block out log quick all with opt lsrr block out log quick all with opt ssrr Reload the IPF rules. Procedure: # ipf -Fa -A -f /etc/ipf/ipf.conf

Additional Identifiers

Rule ID: SV-227799r603266_rule

Vulnerability ID: V-227799

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

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