The plugin 404page was closed on the WordPress Plugin Directory on Saturday. As that is one of 1,000 most popular plugins our systems alerted us to its removal and then we checked things over to see if there was a security issue that might have led to it being removed. While no reason had been given for its removal, in a quick check we found a minor, but rather nasty vulnerability that could an attacker to cause WordPress users to disable their access to the website without intending it. We then used WPDirectory to see if other plugins might have similar code and found that a number of other plugins by the same developer do. Subsequently to us doing that, the vulnerability was fixed in 404page and then subsequently that was credited to Julio Potier, so it appears that was the cause of the closure, but the other plugins have not been fixed yet.

The plugin makes the function dismiss_admin_notice() accessible to anyone logged in to WordPress through WordPress’ AJAX functionality: [Read more]