Passwords can be written as plain text in SQL statements such as CREATE USER, GRANT, and SET PASSWORD, or statements that invoke the PASSWORD() function. If these statements are logged by the MySQL server as written, such passwords become available to anyone with access to the logs. This applies to the general query log, the slow query log, and the binary log (see MySQL Server Logs). To guard against unwarranted exposure to log files, they should be located in a directory that restricts access to only the server and the database administrator.

Replication slaves store the password for the replication master in the master.info file. Retrict this file to be accessible only to the database administrator.

Database backups that include tables or log files containing passwords should be protected using a restricted access mode.