OL 9 must log IPv4 packets with impossible addresses by default.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-271867 | OL09-00-006023 | SV-271867r1092313_rule | CCI-000366 | medium |
| Description | ||||
| The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected. | ||||
| STIG | Date | |||
| Oracle Linux 9 Security Technical Implementation Guide | 2025-05-08 | |||
Details
Check Text (C-271867r1092313_chk)
Verify that OL 9 logs IPv4 martian packets by default.
Check the value of the accept source route variable with the following command:
$ sysctl net.ipv4.conf.default.log_martians
net.ipv4.conf.default.log_martians = 1
If the returned line does not have a value of "1", a line is not returned, or the line is commented out, this is a finding.
Fix Text (F-75824r1092312_fix)
Configure OL 9 to log martian packets on IPv4 interfaces by default.
Add or edit the following line in a single system configuration file in the "/etc/sysctl.d/" directory:
net.ipv4.conf.default.log_martians=1
Load settings from all system configuration files with the following command:
$ sudo sysctl --system