CVE-2025-3083
📋 TL;DR
A vulnerability in MongoDB's mongos query router allows unauthenticated attackers to send specially crafted wire protocol messages that cause the service to crash during command validation. This affects MongoDB v5.0 before 5.0.31, v6.0 before 6.0.20, and v7.0 before 7.0.16. Organizations running vulnerable mongos instances are at risk of denial of service.
💻 Affected Systems
- MongoDB mongos
📦 What is this software?
Mongodb by Mongodb
Mongodb by Mongodb
Mongodb by Mongodb
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service for MongoDB sharded clusters, disrupting all database operations that rely on mongos routing until service restart.
Likely Case
Intermittent mongos crashes causing application downtime and connection failures in sharded MongoDB deployments.
If Mitigated
Minimal impact if mongos instances are behind proper network controls and load balancers with automatic failover.
🎯 Exploit Status
The vulnerability requires crafting specific wire protocol messages but doesn't require authentication, making exploitation straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: MongoDB v5.0.31, v6.0.20, v7.0.16
Vendor Advisory: https://jira.mongodb.org/browse/SERVER-103152
Restart Required: Yes
Instructions:
1. Identify affected mongos instances. 2. Download patched version from MongoDB website. 3. Stop mongos service. 4. Install updated version. 5. Restart mongos service. 6. Verify version and functionality.
🔧 Temporary Workarounds
Network Access Control
allRestrict network access to mongos instances to only trusted sources
# Use firewall rules to limit access
# Example for Linux iptables:
iptables -A INPUT -p tcp --dport 27017 -s trusted_ip_range -j ACCEPT
iptables -A INPUT -p tcp --dport 27017 -j DROP
Load Balancer Health Checks
allConfigure load balancers to automatically remove and restart crashed mongos instances
# Configure health check in your load balancer
# Example nginx configuration:
upstream mongos_backend {
server mongos1:27017 max_fails=3 fail_timeout=30s;
server mongos2:27017 max_fails=3 fail_timeout=30s;
health_check interval=5s fails=3 passes=2;
}
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to limit access to mongos instances
- Deploy additional mongos instances behind load balancers with automatic failover to maintain availability during crashes
🔍 How to Verify
Check if Vulnerable:
Check mongos version: connect to mongos and run 'db.version()' or check startup logs for version informationCheck Version:
mongos --version # or from mongo shell: db.version()Verify Fix Applied:
After patching, verify version is 5.0.31+, 6.0.20+, or 7.0.16+ and monitor for crashes📡 Detection & Monitoring
Log Indicators:
- Unexpected mongos process termination
- Connection resets during command validation
- Error messages related to wire protocol parsing
Network Indicators:
- Multiple TCP connections to mongos port 27017 followed by service unavailability
- Unusual wire protocol traffic patterns
SIEM Query:
source="mongos.log" AND ("fatal" OR "assertion" OR "aborting" OR "Segmentation fault")