Stack-based buffer overflow in the acl_get function in Oracle MySQL 5.5.19 and other versions through 5.5.28, and 5.1.53 and other versions through 5.1.66, and MariaDB 5.5.2.x before 5.5.28a, 5.3.x before 5.3.11, 5.2.x before 5.2.13 and 5.1.x before 5.1.66, allows remote authenticated users to execute arbitrary code via a long argument to the GRANT FILE command.

Multiple SQL injection vulnerabilities in the replication code in Oracle MySQL possibly before 5.5.29, and MariaDB 5.1.x through 5.1.62, 5.2.x through 5.2.12, 5.3.x through 5.3.7, and 5.5.x through 5.5.25, allow remote authenticated users to execute arbitrary SQL commands via vectors related to the binary log. NOTE: as of 20130116, Oracle has not commented on claims from a downstream vendor that the fix in MySQL 5.5.29 is incomplete.

Oracle MySQL 5.5.38 and earlier, 5.6.19 and earlier, and MariaDB 5.5.28a, 5.3.11, 5.2.13, 5.1.66, and possibly other versions, generates different error messages with different time delays depending on whether a user name exists, which allows remote attackers to enumerate valid usernames.

sql/password.c in Oracle MySQL 5.1.x before 5.1.63, 5.5.x before 5.5.24, and 5.6.x before 5.6.6, and MariaDB 5.1.x before 5.1.62, 5.2.x before 5.2.12, 5.3.x before 5.3.6, and 5.5.x before 5.5.23, when running in certain environments with certain implementations of the memcmp function, allows remote attackers to bypass authentication by repeatedly authenticating with the same incorrect password, which eventually causes a token comparison to succeed due to an improperly-checked return value.