The 404 to 301 plugin for WordPress is vulnerable to authorization bypass due to missing capability checks on the open_redirect & save_redirect functions in versions up to, and including, 3.0.7. This makes it possible for authenticated attackers to view, create and edit redirections.

The 404 to 301 – Redirect, Log and Notify 404 Errors WordPress plugin before 3.0.9 does not have CSRF check in place when cleaning the logs, which could allow attacker to make a logged in admin delete all of them via a CSRF attack

The 404-to-301 plugin before 2.0.3 for WordPress has SQL injection.