Unspecified vulnerability in the MySQL Server component in Oracle MySQL 5.5.19 and earlier allows remote authenticated users to affect availability via unknown vectors related to Server Optimizer.

MySQL 4.1 before 4.1.21 and 5.0 before 5.0.24 allows a local user to access a table through a previously created MERGE table, even after the user's privileges are revoked for the original table, which might violate intended security policy.

MySQL 5.0.18 and earlier allows local users to bypass logging mechanisms via SQL queries that contain the NULL character, which are not properly handled by the mysql_real_query function. NOTE: this issue was originally reported for the mysql_query function, but the vendor states that since mysql_query expects a null character, this is not an issue for mysql_query.

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.

mysqlbug in MySQL allows local users to overwrite arbitrary files via a symlink attack on the failed-mysql-bugreport temporary file.

MySQL 3.20 through 4.1.0 uses a weak algorithm for hashed passwords, which makes it easier for attackers to decrypt the password via brute force methods.

Buffer overflow in get_salt_from_password from sql_acl.cc for MySQL 4.0.14 and earlier, and 3.23.x, allows attackers with ALTER TABLE privileges to execute arbitrary code via a long Password field.

MySQL 3.23.55 and earlier creates world-writeable files and allows mysql users to gain root privileges by using the "SELECT * INFO OUTFILE" operator to overwrite a configuration file and cause mysql to run as root upon restart, as demonstrated by modifying my.cnf.

Double-free vulnerability in mysqld for MySQL before 3.23.55 allows attackers with MySQL access to cause a denial of service (crash) via mysql_change_user.

The COM_CHANGE_USER command in MySQL 3.x before 3.23.54, and 4.x before 4.0.6, allows remote attackers 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.