The router must be configured to drop all fragmented Internet Control Message Protocol (ICMP) packets destined to itself.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-207134SRG-NET-000205SRG-NET-000205-RTR-000002SV-207134r604135_rule2024-05-285
Description
Fragmented ICMP packets can be generated by hackers for DoS attacks such as Ping O' Death and Teardrop. It is imperative that all fragmented ICMP packets are dropped.
ℹ️ Check
Review the access control list (ACL) or filter for the router receive path. Verify that it will drop all fragmented ICMP packets destined to itself. If the router is not configured with a receive-path filter to drop all fragmented ICMP packets, this is a finding. Note: If the platform does not support the receive path filter, verify that all Layer 3 interfaces have an ingress ACL to control what packets are allowed to be destined to the router for processing.
✔️ Fix
Ensure all routers have their receive path filter configured to drop all fragmented ICMP packets.