Vulnerability Discussion

The Apple System Logs (ASL) must be configured to be writable by root and readable only by the root user and group wheel. To achieve this, ASL log files must be configured to mode 640 permissive or less; thereby preventing normal users from reading, modifying, or deleting audit logs. System logs frequently contain sensitive information that could be used by an attacker. Setting the correct permissions mitigates this risk.

Satisfies: SRG-OS-000205-GPOS-00083,SRG-OS-000206-GPOS-00084

Check

Verify the macOS system is configured with Apple System Log files to mode 640 or less permissive with the following command:

/usr/bin/stat -f '%A:%N' $(/usr/bin/grep -e '^>' /etc/asl.conf /etc/asl/* | /usr/bin/awk '{ print $2 }') 2> /dev/null | /usr/bin/awk '!/640/{print $1}' | /usr/bin/wc -l | /usr/bin/tr -d ' '

If the result is not "0", this is a finding.

Fix

Configure the macOS system with Apple System Log files to mode 640 with the following command:

/bin/chmod 640 $(/usr/bin/stat -f '%A:%N' $(/usr/bin/grep -e '^>' /etc/asl.conf /etc/asl/* | /usr/bin/awk '{ print $2 }') 2> /dev/null | /usr/bin/awk -F":" '!/640/{print $2}')