The Feed Them Social – for Twitter feed, Youtube and more plugin for WordPress is vulnerable to deserialization of untrusted input via the 'fts_url' parameter in versions up to, and including 2.9.8.5. This makes it possible for unauthenticated attackers to call files using a PHAR wrapper that will deserialize the data and call arbitrary PHP Objects that can be used to perform a variety of malicious actions granted a POP chain is also present. It also requires that the attacker is successful in uploading a file with the serialized payload.
CWE-502, CWE-502, CWE-502