MySQL is a popular multi-threaded, multi-user SQL server.
Sergei Golubchik reported that MySQL imposes no restrictions on the specification of "DATA DIRECTORY" or "INDEX DIRECTORY" in SQL "CREATE TABLE" statements.
An authenticated remote attacker could create MyISAM tables, specifying DATA or INDEX directories that contain future table files by other database users, or existing table files in the MySQL data directory, gaining access to those tables.
There is no known workaround at this time.
All MySQL users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-db/mysql-5.0.60-r1"