Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin <= 2.13.1 - Unauthenticated PHP Object Injection

The Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 2.13.1. This is due to deserialization of untrusted input. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.

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: Ultimate Member 2.14.0 closes this, and updating the plugin is the step that ends it.

• Firewall
• Scanner
• Login Security