CVE-2020-6058
📋 TL;DR
CVE-2020-6058 is a critical out-of-bounds read vulnerability in MiniSNMPD version 1.4 that allows attackers to read sensitive memory contents and cause denial of service. Attackers can exploit this by sending specially crafted SNMP packets to vulnerable servers. Organizations running MiniSNMPD 1.4 are affected.
💻 Affected Systems
- MiniSNMPD
📦 What is this software?
Minisnmpd by Minisnmpd Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through memory disclosure leading to credential theft, followed by service disruption and potential lateral movement.
Likely Case
Service disruption (DoS) and leakage of sensitive information from memory, potentially exposing credentials or configuration data.
If Mitigated
Limited impact with proper network segmentation and SNMP access controls, potentially only causing service restart.
🎯 Exploit Status
Exploitation requires sending crafted SNMP packets to UDP port 161. Public proof-of-concept code exists in vulnerability reports.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.5 or later
Vendor Advisory: https://github.com/troglobit/mini-snmpd/releases
Restart Required: Yes
Instructions:
1. Download MiniSNMPD 1.5+ from GitHub. 2. Stop the current MiniSNMPD service. 3. Install the new version. 4. Restart the service. 5. Verify the version is updated.
🔧 Temporary Workarounds
Network Access Control
linuxRestrict SNMP access to trusted networks only using firewall rules.
iptables -A INPUT -p udp --dport 161 -s TRUSTED_NETWORK -j ACCEPT
iptables -A INPUT -p udp --dport 161 -j DROP
Service Disablement
linuxDisable MiniSNMPD service if not required.
systemctl stop mini-snmpd
systemctl disable mini-snmpd
🧯 If You Can't Patch
- Implement strict network segmentation to isolate SNMP traffic to management networks only.
- Deploy intrusion detection systems to monitor for SNMP exploitation attempts and alert on anomalous packets.
🔍 How to Verify
Check if Vulnerable:
Check if MiniSNMPD version 1.4 is running: 'ps aux | grep mini-snmpd' and check version in output or configuration.Check Version:
mini-snmpd -v 2>/dev/null || grep version /etc/mini-snmpd.confVerify Fix Applied:
Verify the version is 1.5 or higher: 'mini-snmpd -v' or check service status and version in package manager.📡 Detection & Monitoring
Log Indicators:
- SNMP service crashes or restarts in system logs
- Unusual SNMP request patterns in application logs
Network Indicators:
- Malformed SNMP packets to UDP port 161
- High volume of SNMP requests from single sources
SIEM Query:
source_port:161 AND (packet_size:>1500 OR protocol_anomaly:true)