MySQL is a popular open-source, multi-threaded, multi-user SQL database server.
The following vulnerabilities were found and fixed in MySQL:
Oleksandr Byelkin found that ALTER TABLE ... RENAME checks CREATE/INSERT rights of the old table instead of the new one (CAN-2004-0835). Another privilege checking bug allowed users to grant rights on a database they had no rights on.
Dean Ellis found a defect where multiple threads ALTERing the MERGE tables to change the UNION could cause the server to crash (CAN-2004-0837). Another crash was found in MATCH ... AGAINST() queries with missing closing double quote.
Finally, a buffer overrun in the mysql_real_connect function was found by Lukasz Wojtow (CAN-2004-0836).
The privilege checking issues could be used by remote users to bypass their rights on databases. The two crashes issues could be exploited by a remote user to perform a Denial of Service attack on MySQL server. The buffer overrun issue could also be exploited as a Denial of Service attack, and may allow to execute arbitrary code with the rights of the MySQL daemon (typically, the "mysql" user).
There is no known workaround at this time.
All MySQL users should upgrade to the latest version:
# emerge sync
# emerge -pv ">=dev-db/mysql-4.0.21"
# emerge ">=dev-db/mysql-4.0.21"