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How the mentioned CVE works (technical details):
The vulnerability exists in Winter CMS’s Tailor and CMS editor extensions. A flaw in fine-grained permission enforcement allows backend users with the broad `editor` role—but explicitly denied the sub-permissions `editor.cms_assets` or editor.tailor_blueprints—to still perform restricted file operations. The core issue is missing sub-permission checks on asset and blueprint file commands (create, delete, rename, move, upload, directory creation). Additionally, an operator precedence error in the Tailor navigation logic incorrectly evaluates permission conditions, exposing the theme blueprint directory tree (file paths and structure) to users lacking editor.tailor_blueprints. Exploitation requires an uncommon permission configuration where `editor` is granted but specific sub-permissions are withheld. Affected operations bypass the intended document‑type permission model, allowing unauthorized file system changes and information disclosure. The flaw impacts versions prior to v3.7.16 and v4.1.16, where patches enforce proper checks and correct navigation node logic.
DailyCVE Form (3 words max per line):
Platform: Winter CMS
Version: Before 3.7.16/4.1.16
Vulnerability: Missing sub-permission checks
Severity: Medium
Date: Not specified
Prediction: Already patched (upgrade)
What Undercode Say (Analytics):
Identify vulnerable version via version.php
curl -s https://target.com/modules/system/version.php | grep -E "3.[0-7].[0-9]{1,2}|4.[bash].[0-9]{1,2}"
Check if editor permissions are misconfigured (requires authenticated session)
List users with 'editor' but without 'editor.cms_assets'
php artisan winter:permission list | grep editor | grep -v editor.cms_assets
Simulate asset file operation bypass (rename theme asset)
curl -X POST -H "X-Winter-Request: 1" -H "Cookie: winter_session=..." \
-d "command=rename&path=/themes/demo/assets/css/style.css&new_path=/themes/demo/assets/css/malicious.css" \
https://target.com/backend/cms/asset
Exploit:
Authenticated backend user with `editor` role but denied `editor.cms_assets` can:
– Upload a malicious PHP file to `/themes/demo/assets/`
– Rename or delete existing theme assets
– Create arbitrary directories under `themes//assets/`
With `editor.tailor_blueprints` denied, attacker can:
- Enumerate blueprint YAML files via Tailor navigation tree
- Delete, rename, or upload blueprint files (e.g.,
blueprints/user.yaml) - Move blueprint files to accessible locations
Protection from this CVE:
- Upgrade to Winter CMS v3.7.16 or v4.1.16 immediately
- If upgrade impossible, remove `editor` permission from all untrusted backend users
- Restrict `editor` access to fully trusted administrators only
- Audit existing backend users: `php artisan winter:permission list` – revoke `editor` where sub‑permissions were withheld
Impact:
- Confidentiality: Blueprint directory tree disclosure (file paths, structure)
- Integrity: Unauthorized modification, deletion, or addition of theme assets and blueprint files
- Availability: Could delete critical theme files causing site malfunction
- Scope: Only backend users with unusual permission overrides; default configurations unaffected
- Exploit complexity: Low – authenticated user with valid session; no special tools required
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Sources:
Reported By: github.com
Extra Source Hub:
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