Vulnerability Discussion

Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat.

Satisfies: SRG-OS-000327-GPOS-00127, SRG-OS-000326-GPOS-00126

Check

Verify that AlmaLinux OS 9 is configured to audit the execution of the "execve" system call with the following command:

$ auditctl -l | grep execve

-a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -F key=execpriv
-a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -F key=execpriv
-a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -F key=execpriv
-a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -F key=execpriv

If the command does not return all lines, or the lines are commented out, this is a finding.

Fix

Configure AlmaLinux OS 9 to generate audit records upon successful/unsuccessful attempts to use the "sudo" command.

Add the following to the "/etc/audit/rules.d/audit.rules" file:

-a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k execpriv
-a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k execpriv
-a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k execpriv
-a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k execpriv

Merge the rules into /etc/audit/audit.rules:

$ augenrules --load