MySQL 5.0 before 5.0.66, 5.1 before 5.1.26, and 6.0 before 6.0.6 does not properly handle a b'' (b single-quote single-quote) token, aka an empty bit-string literal, which allows remote attackers to cause a denial of service (daemon crash) by using this token in a SQL statement.

MySQL 5.0.x before 5.0.51a, 5.1.x before 5.1.23, and 6.0.x before 6.0.4 does not update the DEFINER value of a view when the view is altered, which allows remote authenticated users to gain privileges via a sequence of statements including a CREATE SQL SECURITY DEFINER VIEW statement and an ALTER VIEW statement.

The federated engine in MySQL 5.0.x before 5.0.51a, 5.1.x before 5.1.23, and 6.0.x before 6.0.4, when performing a certain SHOW TABLE STATUS query, allows remote MySQL servers to cause a denial of service (federated handler crash and daemon crash) via a response that lacks the minimum required number of columns.

The mysql_change_db function in MySQL 5.0.x before 5.0.40 and 5.1.x before 5.1.18 does not restore THD::db_access privileges when returning from SQL SECURITY INVOKER stored routines, which allows remote authenticated users to gain privileges.

MySQL before 4.1.21, 5.0 before 5.0.25, and 5.1 before 5.1.12, when run on case-sensitive filesystems, allows remote authenticated users to create or access a database when the database name differs only in case from a database for which they have permissions.

MySQL before 5.0.25 and 5.1 before 5.1.12 evaluates arguments of suid routines in the security context of the routine's definer instead of the routine's caller, which allows remote authenticated users to gain privileges through a routine that has been made available using GRANT EXECUTE.

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.

Off-by-one buffer overflow in the Instance_options::complete_initialization function in instance_options.cc in the Instance Manager in MySQL before 5.0.23 and 5.1 before 5.1.12 might allow local users to cause a denial of service (application crash) via unspecified vectors, which triggers the overflow when the convert_dirname function is called. NOTE: the vendor has disputed this issue via e-mail to CVE, saying that it is only exploitable when the user has access to the configuration file or the Instance Manager daemon. Due to intended functionality, this level of access would already allow the user to disrupt program operation, so this does not cross security boundaries and is not a vulnerability