This rule checks if the configured MySQL error log file is owned by the
user and belongs to the specified log group. As well as assert that other users
and groups do not have read/write/execute access to the log file.
Keeping the log file access restricted to only its interested users and processes is a way of avoiding displaying system vulnerabilities and undesired permission exceptions on your database system.
As stated on the of least privilege principle: user, program, or process should have only the bare minimum privileges necessary to perform its function.