Fluent Forms 5.1.16 - 6.1.0 - Subscriber+ PHP Object Injection To Arbitrary File Read

Description

The plugin is vulnerable to PHP Object Injection in versions 5.1.16 to 6.1.0 via deserialization of untrusted input in the parseUserProperties function. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a PHP Object. The additional presence of a POP chain allows attackers to read arbitrary files. If allow_url_include is enabled on the server, remote code execution is possible.