GHSA-3pvf-vxrv-hh9c Craft CMS: Low-privilege users could read private asset contents when editing an asset (IDOR)

• Packagist craftcms/cms: >= 4.0.0-RC1, < 4.17.8 → fixed in 4.17.8 • Packagist craftcms/cms: >= 5.0.0-RC1, < 5.9.14 → fixed in 5.9.14

Summary A low-privileged authenticated user can read private asset content by calling `assets/edit-image` with an arbitrary `assetId` that they are not authorized to view. The endpoint returns image bytes (or a preview redirect) without enforcing a per-asset view authorization check, leading to potential unauthorized disclosure of private files. Details Root cause: • A user-controlled object reference (`assetId`) is used to load and return sensitive content. • The action does not verify whether the current user is authorized to view that asset. • This creates an authenticated IDOR / authorization bypass. Impact • Craft installations where private/non-public assets exist and low-privileged users can authenticate. Resources https://github.com/craftcms/cms/commit/7290d91639e