The Backup Migration plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.4.6 via deserialization of untrusted input in the recursive_unserialize_replace function. This makes it possible for unauthenticated attackers to inject a PHP Object. The additional presence of a POP chain allows attackers to delete arbitrary files, retrieve sensitive data, or execute code. An administrator must create a staging site in order to trigger the exploit.
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//backup-backup/tags/1.4.6/includes/database/search-replace.php#L46
- https://plugins.trac.wordpress.org/browser/backup-backup/tags/1.4.6.1/includes/database/search-replace.php#L46
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d5a0c514-5200-47f4-9d2e-684d68946b9a?source=cve