CVE-2020-6060
📋 TL;DR
A stack buffer overflow vulnerability in MiniSNMPD version 1.4 allows attackers to cause denial of service by initiating multiple SNMP connections with specific timing. This affects systems running the vulnerable MiniSNMPD service, potentially disrupting network monitoring.
💻 Affected Systems
- MiniSNMPD
📦 What is this software?
Minisnmpd by Minisnmpd Project
⚠️ Risk & Real-World Impact
Worst Case
Complete service crash leading to denial of service, potentially allowing remote code execution if the overflow can be controlled to execute arbitrary code.
Likely Case
Service crash and denial of service, disrupting SNMP monitoring capabilities.
If Mitigated
Limited impact if service is behind firewalls or not internet-facing, with quick restart possible.
🎯 Exploit Status
Exploit requires timing multiple connections but no authentication or special privileges needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.5 or later
Vendor Advisory: https://github.com/troglobit/mini-snmpd
Restart Required: Yes
Instructions:
1. Download latest version from GitHub. 2. Stop MiniSNMPD service. 3. Install new version. 4. Restart service.
🔧 Temporary Workarounds
Firewall Restriction
linuxBlock external access to SNMP port (161/UDP)
iptables -A INPUT -p udp --dport 161 -j DROP
Service Disable
linuxTemporarily disable MiniSNMPD if not essential
systemctl stop mini-snmpd
systemctl disable mini-snmpd
🧯 If You Can't Patch
- Implement network segmentation to restrict SNMP traffic to trusted management networks only.
- Use rate limiting on SNMP connections to prevent the timing attack sequence.
🔍 How to Verify
Check if Vulnerable:
Check MiniSNMPD version: 'mini-snmpd -v' or check running process version.Check Version:
mini-snmpd -v 2>&1 | grep versionVerify Fix Applied:
Verify version is 1.5 or later and service remains stable under connection testing.📡 Detection & Monitoring
Log Indicators:
- Multiple connection attempts to SNMP port in short timeframe
- Service crash/restart logs
Network Indicators:
- Unusual spike in UDP/161 traffic from single source
- Multiple SNMP connection attempts with timing patterns
SIEM Query:
source_port=161 AND (event_count > 10 WITHIN 1s) OR process_name="mini-snmpd" AND event="crash"