Critical Rails Flaw Lets Attackers Write Server Files via Crafted ImageMagick Uploads

A critical flaw in Ruby on Rails could allow an unauthenticated attacker to write arbitrary files on an app’s server by uploading a crafted file if the app processes uploads using ImageMagick. The Rails project disclosed the flaw in an advisory and fixed it in versions 8.1.4.1 and 8.0.5.2.

The flaw is in Active Storage, the part of Rails that handles file uploads. Some apps store