CVE-2025-65223
📋 TL;DR
A buffer overflow vulnerability exists in Tenda AC21 routers version V16.03.08.16 via the urls parameter in the /goform/saveParentControlInfo endpoint. This allows attackers to potentially execute arbitrary code or crash the device. Users running this specific firmware version are affected.
💻 Affected Systems
- Tenda AC21
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, allowing attacker to intercept traffic, modify settings, or use the router as an attack platform.
Likely Case
Denial of service causing router reboot or instability, disrupting network connectivity.
If Mitigated
Limited impact if the vulnerable endpoint is not accessible due to network segmentation or access controls.
🎯 Exploit Status
Exploitation requires access to the web interface, which typically requires authentication. The GitHub reference contains technical details about the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
Check Tenda's official website for firmware updates. If available, download and install the latest firmware through the router's web interface.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to the router's web interface
Restrict access to management interface
allUse firewall rules to limit access to the router's web interface to trusted IPs only
🧯 If You Can't Patch
- Isolate the router on a separate network segment
- Disable the Parent Control feature if not needed
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under System Status or similar sectionCheck Version:
Not applicable - check via web interfaceVerify Fix Applied:
Verify firmware version has been updated to a version newer than V16.03.08.16📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/saveParentControlInfo with long urls parameters
- Router reboot logs
Network Indicators:
- Unusual traffic patterns to router management interface
- HTTP requests with abnormally long parameters
SIEM Query:
source="router_logs" AND (uri="/goform/saveParentControlInfo" AND parameter_length>1000)