CVE-2026-2877
📋 TL;DR
A stack-based buffer overflow vulnerability in Tenda A18 routers allows remote attackers to execute arbitrary code by exploiting the strcpy function in the WifiExtraSet component. This affects Tenda A18 routers running firmware version 15.13.07.13. Attackers can compromise the device remotely without authentication.
💻 Affected Systems
- Tenda A18
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full device compromise, persistence, lateral movement to internal networks, and data exfiltration.
Likely Case
Router compromise allowing network traffic interception, DNS hijacking, credential theft, and botnet recruitment.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and network segmentation.
🎯 Exploit Status
Exploit details are publicly disclosed. The vulnerability is in a strcpy function with predictable overflow conditions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware. 3. Upload via router admin interface. 4. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router admin interface
Login to router admin > Advanced > System Tools > Remote Management > Disable
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace affected router with different model/brand
- Place router behind firewall with strict inbound rules blocking HTTP/HTTPS from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or About pageCheck Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version is newer than 15.13.07.13 after update📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to /goform/WifiExtraSet
- Multiple failed login attempts followed by buffer overflow patterns
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains
- Port scanning from router IP
SIEM Query:
source="router_logs" AND (uri="/goform/WifiExtraSet" OR "wpapsk_crypto5g")