What the vulnerability does
Description
WWBN AVideo is an open source video platform. In versions up to and including 26.0, `POST /objects/aVideoEncoder.json.php` accepts a requester-controlled `chunkFile` parameter intended for staged upload chunks. Instead of restricting that path to trusted server-generated chunk locations, the endpoint accepts arbitrary local filesystem paths that pass `isValidURLOrPath()`. That helper allows files under broad server directories including `/var/www/`, the application root, cache, tmp, and `videos`, only rejecting `.php` files. For an authenticated uploader editing their own video, this becomes an arbitrary local file read. The endpoint copies the attacker-chosen local file into the attacker's public video storage path, after which it can be downloaded over HTTP. Commit 59bbd601a3f65a5b18c1d9e4eb11471c0a59214f contains a patch for the issue.
