CVE-2020-10987
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary system commands on Tenda AC15 AC1900 routers via a specific endpoint. Attackers can exploit this by sending crafted POST requests to the goform/setUsbUnload endpoint with malicious deviceName parameters. This affects users running the vulnerable firmware version on these routers.
💻 Affected Systems
- Tenda AC15 AC1900
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the router allowing attackers to install persistent backdoors, intercept all network traffic, pivot to internal networks, and use the router for botnet activities.
Likely Case
Remote code execution leading to router takeover, credential theft, DNS hijacking, and network surveillance.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Exploit is trivial with publicly available proof-of-concept code. The vulnerability is in CISA's Known Exploited Vulnerabilities catalog.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Later versions than 15.03.05.19 (check Tenda website for latest)
Vendor Advisory: https://www.tendacn.com/en/
Restart Required: Yes
Instructions:
1. Log into router admin interface. 2. Navigate to firmware upgrade section. 3. Download latest firmware from Tenda website. 4. Upload and install new firmware. 5. Reboot router after installation.
🔧 Temporary Workarounds
Disable remote administration
allPrevent external access to router admin interface
Login to router admin → System Tools → Remote Management → Disable
Block endpoint via firewall
linuxBlock access to the vulnerable endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "goform/setUsbUnload" --algo bm -j DROP
🧯 If You Can't Patch
- Isolate router in separate VLAN with strict firewall rules
- Implement network monitoring for suspicious POST requests to goform/setUsbUnload
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is exactly 15.03.05.19, device is vulnerable.Check Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
After updating firmware, verify version is newer than 15.03.05.19 and test endpoint is no longer accessible.📡 Detection & Monitoring
Log Indicators:
- POST requests to /goform/setUsbUnload with suspicious deviceName parameters
- Unusual command execution in router logs
Network Indicators:
- HTTP POST to router IP on port 80 with goform/setUsbUnload in URI
- Suspicious outbound connections from router
SIEM Query:
http.method="POST" AND http.uri="/goform/setUsbUnload" AND (deviceName="*;*" OR deviceName="*|*" OR deviceName="*`*")🔗 References
- https://blog.securityevaluators.com/tenda-ac1900-vulnerabilities-discovered-and-exploited-e8e26aa0bc68
- https://www.ise.io/research/
- https://blog.securityevaluators.com/tenda-ac1900-vulnerabilities-discovered-and-exploited-e8e26aa0bc68
- https://www.ise.io/research/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-10987
