CVE-2024-27090
📋 TL;DR
This vulnerability in Decidim allows attackers to access unpublished or private resources by guessing their URLs or slugs. It affects Decidim instances where resources can be embedded, potentially exposing sensitive data. Organizations using vulnerable Decidim versions are at risk.
💻 Affected Systems
- Decidim
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Sensitive unpublished data (participatory processes, proposals, results) could be exposed to unauthorized users, potentially revealing confidential government or organizational information.
Likely Case
Limited data exposure of unpublished resources that attackers can discover through URL guessing or information leakage.
If Mitigated
Minimal impact with proper access controls and monitoring, though some data exposure risk remains until patched.
🎯 Exploit Status
Exploitation requires attackers to discover or guess unpublished resource identifiers, which may be predictable in some configurations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.27.6
Vendor Advisory: https://github.com/decidim/decidim/security/advisories/GHSA-qcj6-vxwx-4rqv
Restart Required: Yes
Instructions:
1. Update Decidim to version 0.27.6 or later using 'bundle update decidim'. 2. Restart the Rails application server. 3. Verify the fix by checking the version with 'bundle show decidim'.
🔧 Temporary Workarounds
Disable embedding of sensitive resources
allTemporarily disable embedding functionality for unpublished or private resources in Decidim configuration
Modify Decidim configuration files to restrict embed endpoints
Implement URL obfuscation
allAdd random identifiers to resource URLs to make guessing more difficult
Implement custom URL generation with secure random tokens
🧯 If You Can't Patch
- Implement strict access controls and monitoring for embed endpoints
- Use web application firewall rules to block suspicious URL patterns
🔍 How to Verify
Check if Vulnerable:
Check Decidim version with 'bundle show decidim' - if version is below 0.27.6, the system is vulnerable.Check Version:
bundle show decidimVerify Fix Applied:
After updating, verify version is 0.27.6 or higher with 'bundle show decidim'. Test that unpublished resources cannot be accessed via embed URLs.📡 Detection & Monitoring
Log Indicators:
- Multiple 200/304 responses to embed endpoints with unpublished resource IDs
- Unusual access patterns to /embed/ routes
Network Indicators:
- HTTP requests to embed endpoints with sequential or guessed resource IDs
SIEM Query:
source="decidim.log" AND (uri_path="/embed/*" OR uri_path="/embeds/*") AND response_status=200 AND user_agent NOT IN ("expected-bot-list")🔗 References
- https://github.com/decidim/decidim/commit/1756fa639ef393ca8e8bb16221cab2e2e7875705
- https://github.com/decidim/decidim/pull/12528
- https://github.com/decidim/decidim/releases/tag/v0.27.6
- https://github.com/decidim/decidim/security/advisories/GHSA-qcj6-vxwx-4rqv
- https://github.com/decidim/decidim/commit/1756fa639ef393ca8e8bb16221cab2e2e7875705
- https://github.com/decidim/decidim/pull/12528
- https://github.com/decidim/decidim/releases/tag/v0.27.6
- https://github.com/decidim/decidim/security/advisories/GHSA-qcj6-vxwx-4rqv
