The LearnPress plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 4.4.10 via deserialization of untrusted input from the checkout-email request parameter during the checkout AJAX action. The value is passed through sanitize_text_field(), which does not strip serialized object syntax, then stored in the LearnPress session table and later fed to LP_Helper::maybe_unserialize() → unserialize() (without an allowed_classes restriction) by LP_Session_Handler::get() on subsequent requests. This makes it possible for unauthenticated attackers to inject a PHP Object.
Weakness
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Potential Mitigations
- Make fields transient to protect them from deserialization.
- An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.
Related Attack Patterns
References
- https://plugins.trac.wordpress.org/browser/learnpress/tags/4.4.9.1/inc/class-lp-ajax.php#L21
- https://plugins.trac.wordpress.org/browser/learnpress/tags/4.4.9.1/inc/class-lp-checkout.php#L377
- https://plugins.trac.wordpress.org/browser/learnpress/tags/4.4.9.1/inc/class-lp-checkout.php#L523
- https://plugins.trac.wordpress.org/browser/learnpress/tags/4.4.9.1/inc/class-lp-session-handler.php#L373
- https://plugins.trac.wordpress.org/changeset?reponame=\u0026old=3750024%40learnpress\u0026new=3750024%40learnpress
- https://www.wordfence.com/threat-intel/vulnerabilities/id/3e28e008-0ec1-4262-9ac0-6170cf8b8bdf?source=cve