Information
Record changes to network environment files or system calls. The below parameters monitors the following system calls, and write an audit event on system call exit:
- sethostname - set the systems host name
- setdomainname - set the systems domain name
Monitoring sethostname and setdomainname will identify potential unauthorized changes to host and domain name of a system. The changing of these names could potentially break security parameters that are set based on those names.
Solution
Note:
- The -w option is deprecated and the rule should be updated in accordance with the Remediation Procedure.
- For best performance, the arch field should be supplied in the rule. The individual permissions will cause the selection of specific system calls that use that kind of access. Not supplying the arch will cause the selection of all system calls which will affect performance as all system calls will be evaluated.
- Edit or create a file in the /etc/audit/rules.d/ directory, ending inrules extension, with the relevant rules to monitor events that modify the system's network environment.
Example:
# printf "
-a always,exit -F arch=b64 -S sethostname,setdomainname -k system-locale
" >> /etc/audit/rules.d/50-system_locale.rules <xhtml:ol start="2"> - Merge and load the rules into active configuration:
# augenrules --load <xhtml:ol start="3"> - Check if reboot is required:
# if [[ $(auditctl -s | grep "enabled") =~ "2" ]]; then printf "Reboot required to load rules\n"; fi