October CMS: Editor Sub-Permission Bypass for Asset and Blueprint File Operations

Fine-grained sub-permission checks for asset and blueprint file operations were not enforced in the CMS and Tailor editor extensions. This only affects backend users who were explicitly granted editor access but had editor.cms_assets or editor.tailor_blueprints specifically withheld, an uncommon permission configuration. In this edge case, such users could perform file operations (create, delete, rename, move, upload) on theme assets or blueprint files despite lacking the required sub-permission. A related operator precedence error in the Tailor navigation also disclosed the theme blueprint directory tree under the same conditions.

Impact

• Only exploitable by authenticated backend users with editor access who have been specifically denied the editor.cms_assets or editor.tailor_blueprints sub-permissions
• Does not affect default permission configurations where editor users typically have all sub-permissions granted
• Users without editor.cms_assets could manipulate theme asset files (delete, rename, move, upload, create directories)
• Users without editor.tailor_blueprints could manipulate blueprint files (delete, rename, move, upload, create directories)
• Users without editor.tailor_blueprints could view the theme blueprint navigation tree, disclosing file paths and directory structure

Patches

The vulnerability has been patched in v3.7.16 and v4.1.16. Fine-grained document type permission checks are now enforced on all asset and blueprint file operation commands, and the navigation node condition logic has been corrected. All users are encouraged to upgrade to the latest patched version.

Workarounds

• Restrict the editor permission to fully trusted administrators only
• Remove the editor permission from any user who should not have asset or blueprint management access