Custom Field Suite <= 2.6.7 - Authenticated (Contributor+) PHP Code Injection via Loop Custom Field

The Custom Field Suite plugin for WordPress is vulnerable to PHP Code Injection in all versions up to, and including, 2.6.7 via the Loop custom field. This is due to insufficient sanitization of input prior to being used in a call to the eval() function. This makes it possible for authenticated attackers, with contributor-level access and above, to execute arbitrary PHP code on the server.

An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: 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. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.

• Firewall
• Scanner
• Alerts