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.