3.5 Ensure 'relay_log_basename' Files Have Appropriate Permissions

Information

MySQL can operate using a variety of log files, each used for different purposes. These are the binary log (which can be encrypted), error log, slow query log, relay log (which can be encrypted), general log, and in the enterprise edition, the audit log (which can be encrypted). Because these are files on the host operating system, they are subject to the permissions and ownership structure provided by the host and may be accessible by users other than the MySQL user. Additionally, using secure key management and at rest MySQL encryption can further protect data from OS users.

Rationale:

Limiting the accessibility of these objects will protect the confidentiality, integrity, and availability of the MySQL logs.

Impact:

If the permissions on the relay logs and binary log files are accidentally changed to exclude the user account which is used to run the MySQL service, then this might break replication.

The binary log file can be used for point in time recovery so this can also affect backup, restore and disaster recovery procedures.

Solution

Execute the following command for each log file location requiring corrected permissions and ownership:

chmod 660 <log file>
chown mysql:mysql <log file>

Default Value:

<datadir> + '/' + <hostname> + '-relay-bin'

See Also

https://workbench.cisecurity.org/files/3844

Item Details

Category: ACCESS CONTROL, MEDIA PROTECTION

References: 800-53|AC-3, 800-53|AC-5, 800-53|AC-6, 800-53|MP-2, CSCv7|14.6

Plugin: Unix

Control ID: 5a24f0d475a79f1010f05aa7968b4a05c10f7947066d3e2b36d0e9e03a766e57