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.
sql_select.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 INFORMATION_SCHEMA table, as originally demonstrated using ORDER BY.