CVE-2020-7921
📋 TL;DR
This vulnerability allows authenticated MongoDB users to bypass IP whitelisting protection after administrative actions like role modifications. It affects MongoDB Server versions 3.6 prior to 3.6.18, 4.0 prior to 4.0.15, 4.2 prior to 4.2.3, and 4.3 prior to 4.3.3.
💻 Affected Systems
- MongoDB Server
📦 What is this software?
Mongodb by Mongodb
Mongodb by Mongodb
Mongodb by Mongodb
Mongodb by Mongodb
⚠️ Risk & Real-World Impact
Worst Case
Authorized users can connect from unauthorized IP addresses, potentially accessing sensitive data or performing unauthorized operations from outside allowed networks.
Likely Case
Users with valid credentials can bypass network access controls, violating security policies and potentially exposing data to unauthorized locations.
If Mitigated
With proper network segmentation and additional authentication layers, impact is limited to policy violation without data compromise.
🎯 Exploit Status
Requires valid user credentials and specific administrative trigger conditions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.6.18, 4.0.15, 4.2.3, 4.3.3
Vendor Advisory: https://jira.mongodb.org/browse/SERVER-45472
Restart Required: Yes
Instructions:
1. Download patched version from MongoDB website. 2. Stop MongoDB service. 3. Backup data and configuration. 4. Install patched version. 5. Restart MongoDB service. 6. Verify version and functionality.
🔧 Temporary Workarounds
Restrict administrative actions
allLimit role modifications and other administrative actions that trigger the serialization issue
Enforce network-level controls
allImplement additional firewall rules and network segmentation beyond MongoDB IP whitelisting
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to limit MongoDB access
- Monitor for unauthorized connection attempts and review authentication logs regularly
🔍 How to Verify
Check if Vulnerable:
Check MongoDB version and compare against affected ranges. Review if IP whitelisting is configured.Check Version:
mongod --versionVerify Fix Applied:
Verify MongoDB version is 3.6.18+, 4.0.15+, 4.2.3+, or 4.3.3+. Test IP whitelisting functionality.📡 Detection & Monitoring
Log Indicators:
- Connection attempts from unauthorized IP addresses by authenticated users
- Role modification events followed by unexpected connections
Network Indicators:
- MongoDB traffic from IPs not in whitelist
- Unexpected network patterns after administrative changes
SIEM Query:
source="mongodb.log" AND ("connection" OR "authenticate") AND NOT src_ip IN whitelist_ips