Duplicate Advisory: Grav: Path Traversal in ImageMedium::watermark() — arbitrary file disclosure via publicly-cached images

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-w3f4-8pj2-599w. This link is maintained to preserve external references.

Original Description

Grav CMS 2.0.10 contains a path traversal vulnerability in ImageMedium::watermark(), which passes its unsanitized $image argument to RocketTheme\Toolbox\ResourceLocator\UniformResourceLocator::findResource(). Because the file:// scheme branch only lexically collapses '..' segments without a realpath/containment check, an editor authoring Markdown image syntax with traversal sequences can cause arbitrary image files outside Grav's media sandbox to be composited into a carrier image, which is then cached and served from a public, unauthenticated URL — disclosing those files to anonymous visitors.