MariaDB, MySQL: Root privilege escalation

Background

MySQL is a popular multi-threaded, multi-user SQL server. MariaDB is an enhanced, drop-in replacement for MySQL.

Description

The Gentoo installation scripts before 2017-09-29 have chown calls for user-writable directory trees, which allows local users to gain privileges by leveraging access to the mysql account for creation of a link.

Impact

A local attacker could escalate privileges to root.

Workaround

There is no known workaround at this time.

Resolution

All MariaDB users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=dev-db/mariadb-10.0.30-r1"

All MySQL users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=dev-db/mysql-5.6.36-r1"