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 4.0.23 and earlier, and 4.1.x up to 4.1.10, uses predictable file names when creating temporary tables, which allows local users with CREATE TEMPORARY TABLE privileges to overwrite arbitrary files via a symlink attack.
mysqlbug in MySQL allows local users to overwrite arbitrary files via a symlink attack on the failed-mysql-bugreport temporary file.