Vulnerability Discussion

The screen saver timeout must be set to 900 seconds or a shorter length of time.

This rule ensures that a full session lock is triggered within no more than 900 seconds of inactivity.

Check

Verify the macOS system is configured to initiate the screen saver timeout after 15 minutes of inactivity with the following command:

/usr/bin/osascript -l JavaScript << EOS
function run() {
let timeout = ObjC.unwrap($.NSUserDefaults.alloc.initWithSuiteName('com.apple.screensaver')\
.objectForKey('idleTime'))
if ( timeout <= 900 ) {
return("true")
} else {
return("false")
}
}
EOS

If the result is not "true", this is a finding.

Fix

Configure the macOS system to initiate the screen saver after 15 minutes of inactivity by installing the "com.apple.screensaver" configuration profile.