Vulnerability Discussion

Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Audit records can be generated from various components within the information system (e.g., module or policy filter).

When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way.

The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible.

Check

Note: If the USBGuard daemon is not installed and enabled, this requirement is not applicable.

Verify AlmaLinux OS 9 enables Linux audit logging of the USBGuard daemon with the following commands.

$ grep AuditBackend /etc/usbguard/usbguard-daemon.conf

AuditBackend=LinuxAudit

If the "AuditBackend" entry does not equal "LinuxAudit", is missing, or the line is commented out, this is a finding.

Fix

Configure AlmaLinux OS 9 to enable Linux audit logging of the USBGuard daemon by adding or modifying the following line in "/etc/usbguard/usbguard-daemon.conf":

AuditBackend=LinuxAudit