Title

The audit system must be configured to audit the execution of privileged functions and prevent all software from executing at higher privilege levels than users executing the software. (Cat II impact)

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

Check Content

Verify the Ubuntu operating system audits the execution of privilege functions. Check if the Ubuntu operating system is configured to audit the execution of the "execve" system call, by running the following command: # sudo grep execve /etc/audit/audit.rules -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 Text

Configure the Ubuntu operating system to audit the execution of the "execve" system call. Add or update the following file system rules to "/etc/audit/audit.rules": -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 The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command: # sudo systemctl restart auditd.service

Additional Identifiers

Rule ID: SV-215060r610931_rule

Vulnerability ID: V-215060

Group Title: SRG-OS-000326-GPOS-00126

Expert Comments

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