In MySQL 3.23.55 and earlier, MySQL would create world-writeable files and allow mysql users to gain root privileges by using the "SELECT * INTO OUTFILE" operator to overwrite a configuration file. This could cause mysql to run as root upon restarting the daemon.
This has been fixed upstream in version 3.23.56, which is provided for Mandrake Linux 9.0 and Corporate Server 2.1 users. The other updated packages have been patched to correct this issue.
For more details, see http://www.mandrakesecure.net/en/advisories/advisory.php?name=MDKSA-2003:057.