Details

Setting icmp_ignore_bogus_error_responses to 1 prevents the kernel from logging bogus responses (RFC-1122 non-compliant) from broadcast reframes, keeping file systems from filling up with useless log messages. Some routers (and some attackers) will send responses that violate RFC-1122 and attempt to fill up a log file system with many useless error messages.

Solution

Set the following parameter in /etc/sysctl.conf or a /etc/sysctl.d/* file: net.ipv4.icmp_ignore_bogus_error_responses = 1

Run the following commands to set the active kernel parameters:
# sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
# sysctl -w net.ipv4.route.flush=1

Supportive Information

The following resource is also helpful.

• https://www.cisco.com/c/en/us/td/docs/security/firepower/623/configuration/guide/fpmc-config-guide-v623.html

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Unix.

References

• 800-53|SC-7(12)
• CSCv6|3
• CSCv6|11

Source

• Tenable.com/audits