PHP object injection in QA Assistants plugin leads to code execution

The QA Assistants – Driven by data plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 5.3.0 via the 'dlevent_ver' parameter. This is due to unrestricted PHP deserialization via wrap_unserialize_static() calling unserialize() without an allowed_classes restriction, combined with serialize_escape() failing to sanitize path traversal sequences in the raw_name parameter. This makes it possible for unauthenticated attackers to inject a PHP Object. The Guzzle FileCookieJar gadget present in the plugin's bundled Composer dependencies can be leveraged to perform an Arbitrary File Write, writing attacker-controlled content to an attacker-chosen filename, which can result in Remote Code Execution. Exploitation requires triggering the qahm_cron_data_manage scheduled event via wp-cron.php to invoke the deserialization sink against a planted queue file, but this endpoint requires no authentication and fires automatically on a two-minute schedule.