MySQL before 4.1.23, 5.0.x before 5.0.42, and 5.1.x before 5.1.18 does not require the DROP privilege for RENAME TABLE statements, which allows remote authenticated users to rename arbitrary tables.
sqlselect.cc in MySQL 5.0.x before 5.0.32 and 5.1.x before 5.1.14 allows remote authenticated users to cause a denial of service (crash) via an EXPLAIN SELECT FROM on the INFORMATIONSCHEMA table, as originally demonstrated using ORDER BY.