Part-DB Attachment Upload Arbitrary PHP Code Execution Vulnerability

Part-DB, an open source inventory management system for electronic components, has a file upload vulnerability leading to arbitrary PHP code execution in versions prior to 2.12.1. The part attachment upload handler stores uploaded files under the web-served media directory using the client-supplied file extension, and its extension blocklist does not include phar.

AttachmentSubmitHandler::renameBlacklistedExtensions() rewrites dangerous extensions such as php, phtml, sh, cgi, py, js, html, and htaccess to .txt, but phar is absent from the list, so a .phar file keeps its extension. Public attachments, the default, are written into public/media/, which is the Apache document root. The shipped Apache configuration routes .phar to PHP-FPM, so the stored file is executed as PHP on request.

The per-attachment-type extension filter is empty by default and is not consulted by the upload handler in a way that blocks this, and a non-admin user in the default users group can create an attachment type with no filter and attach files to parts. Any authenticated user in the default users group can upload a .phar attachment to a part and fetch it under /media/, executing arbitrary PHP as the www-data web user.

• Affected versions: prior to 2.12.1
• Precondition: authenticated user in the default users group
• Exploitability depends on the webserver config; the Docker image contained the vulnerability by default
• Impact: arbitrary PHP code execution as the www-data web user

This issue has been patched in version 2.12.1.