Post Grid and Gutenberg Blocks <= 2.3.11 - Authenticated (Contributor+) PHP Object Injection

The Post Grid and Gutenberg Blocks plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 2.3.11 via deserialization of untrusted input. This makes it possible for authenticated attackers, with contributor-level access and above, 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.

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. None of that substitutes for the fix: Post Grid 2.3.12 closes this, and updating the plugin is the step that ends it.

• Firewall
• Scanner
• Alerts