CVE-2020-26510
📋 TL;DR
Airleader Master devices up to version 6.21 have default credentials that allow attackers to access the Tomcat Manager interface. This enables deployment of malicious .war files leading to remote code execution. Organizations using these devices with default configurations are affected.
💻 Affected Systems
- Airleader Master
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the device, potentially pivoting to internal networks, deploying ransomware, or establishing persistent backdoors.
Likely Case
Attackers deploy web shells or malware to execute arbitrary commands, steal sensitive data, or use the device as a foothold for further attacks.
If Mitigated
If default credentials are changed and Tomcat Manager is not exposed, the attack surface is significantly reduced, though other vulnerabilities might still exist.
🎯 Exploit Status
Exploitation requires knowledge of default credentials but is straightforward once obtained. The advisory includes technical details that facilitate weaponization.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: > 6.21
Vendor Advisory: https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2020-033.txt
Restart Required: Yes
Instructions:
1. Contact Airleader vendor for updated firmware >6.21. 2. Backup device configuration. 3. Apply firmware update following vendor instructions. 4. Verify update completed successfully. 5. Change all default credentials.
🔧 Temporary Workarounds
Change Default Credentials
allImmediately change all default passwords on the device, especially for Tomcat Manager and administrative interfaces.
Restrict Tomcat Manager Access
linuxConfigure firewall rules to block external access to Tomcat Manager port (typically 8080) and restrict to trusted management networks only.
iptables -A INPUT -p tcp --dport 8080 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP
🧯 If You Can't Patch
- Isolate the device on a separate VLAN with strict network segmentation and access controls.
- Implement network monitoring and intrusion detection specifically for traffic to/from the device on port 8080.
🔍 How to Verify
Check if Vulnerable:
Attempt to access the Tomcat Manager interface at http://device_ip:8080/manager/html using default credentials (check vendor documentation for specifics). If login succeeds, device is vulnerable.Check Version:
Check device web interface or console for firmware version information (vendor-specific).Verify Fix Applied:
Verify firmware version is >6.21 and test that default credentials no longer work. Confirm Tomcat Manager is not accessible from untrusted networks.📡 Detection & Monitoring
Log Indicators:
- Failed/successful authentication attempts to Tomcat Manager with default usernames
- Unexpected .war file deployments
- Unusual process execution from Tomcat
Network Indicators:
- Traffic to port 8080 from unexpected sources
- HTTP POST requests to /manager/html/deploy
- Upload of .war files to the device
SIEM Query:
source_ip=* dest_port=8080 (http_method=POST AND uri_path="/manager/html/deploy") OR (http_method=POST AND content_type="application/octet-stream")