Unspecified vulnerability in Drupal before 4.6.11, and 4.7 before 4.7.5, when MySQL is used, allows remote authenticated users to cause a denial of service by poisoning the page cache via unspecified vectors, which triggers erroneous 404 HTTP errors for pages that exist.
The Hotblocks module 6.x-1.x before 6.x-1.8 for Drupal allows remote authenticated users with the "administer hotblocks" permission to cause a denial of service (infinite loop and time out) via a block that references itself.