A denial of service flaw was found in the way MySQL processed EXPLAIN statements for SQL queries of the form:

SELECT ... UNION ... ORDER BY (SELECT ... WHERE ...)

A remote authenticated MySQL user could use this flaw to cause mysqld deamon crash (dereference NULL pointer).

References: [1] http://secunia.com/advisories/41048/ [2] http://dev.mysql.com/doc/refman/5.1/en/news-5-1-49.html

Upstream bug report: [3] http://bugs.mysql.com/bug.php?id=52711

Upstream changesets: [4] http://lists.mysql.com/commits/105750 [5] http://lists.mysql.com/commits/112043

Note: This issue only causes a temporary denial of service, as the mysql daemon shipped with Red Hat Enterprise Linux 5 will be automatically restarted after the crash.

A denial of service flaw was found in the way MySQL processed joins queries, which involved a table with unique SET column. A remote MySQL user could use this flaw to cause mysqld daemon crash.

References: [1] http://secunia.com/advisories/41048/ [2] http://dev.mysql.com/doc/refman/5.1/en/news-5-1-49.html

Upstream bug report: [3] http://bugs.mysql.com/bug.php?id=54575

Note: This issue only causes a temporary denial of service, as the mysql daemon shipped with Red Hat Enterprise Linux 5 will be automatically restarted after the crash.