MySQL is a multi-user, multi-threaded SQL database server. While auditing MySQL, Stefan Esser found security vulnerabilities that can be used to crash the server or allow MySQL users to gain privileges.
A signed integer vulnerability in the COM_TABLE_DUMP package for MySQL 3.x to 3.23.53a, and 4.x to 4.0.5a, allows remote attackers to cause a denial of service (crash or hang) in mysqld by causing large negative integers to be provided to a memcpy call. (CAN-2002-1373)
The COM_CHANGE_USER command in MySQL 3.x to 3.23.53a, and 4.x to 4.0.5a, allows a remote attacker to gain privileges via a brute force attack using a one-character password, which causes MySQL to only compare the provided password against the first character of the real password. (CAN-2002-1374)
The COM_CHANGE_USER command in MySQL 3.x to 3.23.53a, and 4.x to 4.0.5a, allows remote attackers to execute arbitrary code via a long response. (CAN-2002-1375)
The MySQL client library (libmysqlclient) in MySQL 3.x to 3.23.53a, and 4.x to 4.0.5a, does not properly verify length fields for certain responses in the read_rows or read_one_row routines, which allows a malicious server to cause a denial of service and possibly execute arbitrary code. (CAN-2002-1376)
Red Hat Linux Advanced Server 2.1 contains versions of MySQL that are vulnerable to these issues. All users of MySQL are advised to upgrade to these errata packages containing MySQL 3.23.54a which is not vulnerable to these issues.