The Theme Editor WordPress plugin before 2.6 did not validate the GET file parameter before passing it to the download_file() function, allowing administrators to download arbitrary files on the web server, such as /etc/passwd

The Theme Editor plugin for WordPress is vulnerable to deserialization of untrusted input via the 'images_array' parameter in versions up to, and including 2.8. This makes it possible for authenticated attackers with administrative privileges to call files using a PHAR wrapper that will deserialize and call arbitrary PHP Objects that can be used to perform a variety of malicious actions granted a POP chain is also present. It also requires that the attacker is successful in uploading a file with the serialized payload.