Unknown vulnerability in MySQL 3.23.58 and earlier, when a local user has privileges for a database whose name includes a "_" (underscore), grants privileges to other databases that have similar names, which can allow the user to conduct unauthorized activities.

MySQL before 4.0.20 allows remote attackers to cause a denial of service (application crash) via a MATCH AGAINST query with an opening double quote but no closing double quote.

Buffer overflow in the mysql_real_connect function in MySQL 4.x before 4.0.21, and 3.x before 3.23.49, allows remote DNS servers to cause a denial of service and possibly execute arbitrary code via a DNS response with a large address length (h_length).

MySQL 4.x before 4.0.21, and 3.x before 3.23.49, allows attackers to cause a denial of service (crash or hang) via multiple threads that simultaneously alter MERGE table UNIONs.

The mysqlhotcopy script in mysql 4.0.20 and earlier, when using the scp method from the mysql-server package, allows local users to overwrite arbitrary files via a symlink attack on temporary files.