GHSA-9436-3GMP-4F53 grav Server-side Template Injection (SSTI) mitigation bypass

Summary The fix for SSTI using |map, |filter and |reduce twigs implemented in the commit 71bbed1 introduces bypass of the denylist due to incorrect return value from isDangerousFunction, which allows to execute the payload prepending double backslash \ Details The isDangerousFunction check in...

Design/Logic Flaw

Grav is a file-based Web-platform built in PHP. Grav is subject to a server side template injection SSTI vulnerability. The fix for another SSTI vulnerability using |map, |filter and |reduce twigs implemented in the commit 71bbed1 introduces bypass of the denylist due to incorrect return value fr...