| Dmitry Teselkin | af730f9 | 2018-08-16 11:29:55 +0300 | [diff] [blame] | 1 | # 3.2.6 Ensure bogus ICMP responses are ignored |
| 2 | # |
| 3 | # Description |
| 4 | # =========== |
| 5 | # Setting icmp_ignore_bogus_error_responses to 1 prevents the kernel from |
| 6 | # logging bogus responses (RFC-1122 non-compliant) from broadcast reframes, |
| 7 | # keeping file systems from filling up with useless log messages. |
| 8 | # |
| 9 | # Rationale |
| 10 | # ========= |
| 11 | # Some routers (and some attackers) will send responses that violate RFC-1122 |
| 12 | # and attempt to fill up a log file system with many useless error messages. |
| 13 | # |
| 14 | # Audit |
| 15 | # ===== |
| 16 | # |
| 17 | # Run the following commands and verify output matches: |
| 18 | # |
| 19 | # # sysctl net.ipv4.icmp_ignore_bogus_error_responses |
| 20 | # net.ipv4.icmp_ignore_bogus_error_responses = 1 |
| 21 | # |
| 22 | # Remediation |
| 23 | # =========== |
| 24 | # |
| 25 | # Set the following parameter in the /etc/sysctl.conf file: |
| 26 | # |
| 27 | # net.ipv4.icmp_ignore_bogus_error_responses = 1 |
| 28 | # |
| 29 | # Run the following commands to set the active kernel parameters: |
| 30 | # |
| 31 | # # sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1 |
| 32 | # # sysctl -w net.ipv4.route.flush=1 |
| 33 | |
| 34 | parameters: |
| 35 | linux: |
| 36 | system: |
| 37 | kernel: |
| 38 | sysctl: |
| 39 | net.ipv4.icmp_ignore_bogus_error_responses: 1 |