CVE-2016-20001
📋 TL;DR
This vulnerability in Drupal's REST/JSON module allows attackers to bypass node access controls and view restricted content. It affects Drupal 7.x sites using the REST/JSON module version 7.x-1.x. The module is not covered by Drupal's official security policy, leaving sites more vulnerable.
💻 Affected Systems
- Drupal REST/JSON module
📦 What is this software?
Rest\/json by Rest\/json Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers can access all restricted content including private user data, confidential documents, and unpublished content, potentially leading to data breaches and compliance violations.
Likely Case
Unauthorized access to sensitive content that should be restricted based on user roles and permissions, compromising data confidentiality.
If Mitigated
With proper access controls and monitoring, impact is limited to potential exposure of some restricted content rather than full system compromise.
🎯 Exploit Status
The vulnerability is in access control logic, making exploitation straightforward. Public advisories provide enough detail for attackers to craft exploits.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to REST/JSON module version that addresses SA-CONTRIB-2016-033
Vendor Advisory: https://www.drupal.org/node/2744889
Restart Required: No
Instructions:
1. Backup your Drupal site. 2. Update the REST/JSON module to the patched version. 3. Clear Drupal caches. 4. Test REST endpoints to ensure proper access controls.
🔧 Temporary Workarounds
Disable REST/JSON module
allTemporarily disable the vulnerable module until patching is possible
drush dis rest_json
Or disable via Drupal admin interface at /admin/modules
Restrict REST endpoint access
linuxUse web server configuration to restrict access to REST endpoints
Add IP restrictions or authentication requirements to REST endpoints in Apache/Nginx config
🧯 If You Can't Patch
- Disable the REST/JSON module immediately
- Implement network-level restrictions to block external access to REST endpoints
🔍 How to Verify
Check if Vulnerable:
Check if REST/JSON module version 7.x-1.x is enabled in Drupal at /admin/modules or using 'drush pml | grep rest_json'Check Version:
drush pml --status=enabled --type=module | grep rest_jsonVerify Fix Applied:
Test REST endpoints with unauthorized users to ensure they cannot access restricted content📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to REST endpoints
- Unusual patterns of node access via REST API
- 403 errors followed by successful 200 responses
Network Indicators:
- Unusual traffic to /rest/* endpoints from unauthorized IPs
- Bursts of REST API requests for restricted content
SIEM Query:
source="drupal" AND (uri_path="/rest/*" OR module="rest_json") AND (response_code=200) AND (user_role!="authenticated" OR user_id=0)