QA Assistants <= 5.3.0 - Unauthenticated PHP Object Injection to Remote Code Execution via 'raw_name' and 'dlevent_ver' Parameters

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.

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: QA Assistants 5.3.0.1 closes this, and updating the plugin is the step that ends it.

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