(RHSA-2010:0109) Moderate: mysql security update

MySQL is a multi-user, multi-threaded SQL database server. It consists of
the MySQL server daemon (mysqld) and many client programs and libraries.

It was discovered that the MySQL client ignored certain SSL certificate
verification errors when connecting to servers. A man-in-the-middle
attacker could use this flaw to trick MySQL clients into connecting to a
spoofed MySQL server. (CVE-2009-4028)

Note: This fix may uncover previously hidden SSL configuration issues, such
as incorrect CA certificates being used by clients or expired server
certificates. This update should be carefully tested in deployments where
SSL connections are used.

A flaw was found in the way MySQL handled SELECT statements with subqueries
in the WHERE clause, that assigned results to a user variable. A remote,
authenticated attacker could use this flaw to crash the MySQL server daemon
(mysqld). This issue only caused a temporary denial of service, as the
MySQL daemon was automatically restarted after the crash. (CVE-2009-4019)

When the “datadir” option was configured with a relative path, MySQL did
not properly check paths used as arguments for the DATA DIRECTORY and INDEX
DIRECTORY directives. An authenticated attacker could use this flaw to
bypass the restriction preventing the use of subdirectories of the MySQL
data directory being used as DATA DIRECTORY and INDEX DIRECTORY paths.
(CVE-2009-4030)

Note: Due to the security risks and previous security issues related to the
use of the DATA DIRECTORY and INDEX DIRECTORY directives, users not
depending on this feature should consider disabling it by adding
“symbolic-links=0” to the “[mysqld]” section of the “my.cnf” configuration
file. In this update, an example of such a configuration was added to the
default “my.cnf” file.

All MySQL users are advised to upgrade to these updated packages, which
contain backported patches to resolve these issues. After installing this
update, the MySQL server daemon (mysqld) will be restarted automatically.