MySQL 5.x before 5.0.36 allows local users to cause a denial of service (database crash) by performing information_schema table subselects and using ORDER BY to sort a single-row result, which prevents certain structure elements from being initialized and triggers a NULL dereference in the filesort function.

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.