CVE-2022-26278
📋 TL;DR
CVE-2022-26278 is a critical stack overflow vulnerability in Tenda AC9 routers that allows remote attackers to execute arbitrary code via the time parameter in the PowerSaveSet function. This affects Tenda AC9 routers running firmware version 15.03.2.21_cn. Attackers can potentially gain full control of affected devices.
💻 Affected Systems
- Tenda AC9
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent backdoor installation, credential theft, network pivoting, and participation in botnets.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a foothold into the network.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Public exploit code available on GitHub. No authentication required for exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates
2. If available, download latest firmware
3. Access router admin interface
4. Navigate to firmware upgrade section
5. Upload and install new firmware
6. Reboot router
🔧 Temporary Workarounds
Disable WAN Management
allPrevent external access to router management interface
Network Segmentation
allIsolate router on separate VLAN with restricted access
🧯 If You Can't Patch
- Replace affected router with different model or vendor
- Place router behind firewall with strict inbound rules
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is exactly 15.03.2.21_cn, device is vulnerable.Check Version:
Check router web interface or use nmap to identify firmware versionVerify Fix Applied:
Verify firmware version has changed from 15.03.2.21_cn to a newer version.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to PowerSaveSet endpoint
- Multiple failed exploit attempts
- Unexpected configuration changes
Network Indicators:
- Unusual outbound connections from router
- Traffic patterns indicating command and control
SIEM Query:
source="router" AND (uri="/goform/PowerSaveSet" OR method="POST" AND uri CONTAINS "PowerSaveSet")