Stack-based buffer overflow in the aclget 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.
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.