CVE-2022-25546
📋 TL;DR
Tenda AX1806 routers running firmware v1.0.0.1 contain a stack overflow vulnerability in the formSetSysToolDDNS function. Attackers can exploit this by sending specially crafted requests to the ddnsUser parameter, causing a Denial of Service (DoS) that crashes the device. This affects all users of Tenda AX1806 routers with the vulnerable firmware version.
💻 Affected Systems
- Tenda AX1806
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical power cycle, potentially leading to extended network downtime and loss of connectivity for all connected devices.
Likely Case
Router becomes unresponsive, requiring manual reboot and causing temporary network disruption for connected users.
If Mitigated
If isolated from untrusted networks, minimal impact with only authorized users potentially triggering the vulnerability.
🎯 Exploit Status
Exploitation requires access to the web interface, which typically requires authentication. However, if default credentials are unchanged or other vulnerabilities exist, this could be chained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch available. Check Tenda's website for firmware updates. If an update exists, download from official sources and apply through the router's web interface under System Tools > Firmware Upgrade.
🔧 Temporary Workarounds
Disable DDNS Service
allTurn off the Dynamic DNS feature to prevent exploitation via the vulnerable parameter.
Restrict Web Interface Access
allLimit access to the router's web management interface to trusted IP addresses only.
🧯 If You Can't Patch
- Isolate the router from untrusted networks and the internet if possible.
- Change default credentials and implement strong authentication for the web interface.
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under System Tools > Firmware Upgrade. If version is exactly v1.0.0.1, the device is vulnerable.Check Version:
No CLI command available. Must check via web interface at http://router_ip or through router's admin panel.Verify Fix Applied:
Verify firmware version has been updated to a version later than v1.0.0.1.📡 Detection & Monitoring
Log Indicators:
- Router crash logs, web interface access logs showing requests to DDNS configuration endpoints with unusual payloads
Network Indicators:
- Sudden loss of connectivity to router, HTTP requests to /goform/setSysToolDDNS with large ddnsUser parameter values
SIEM Query:
Not applicable for typical home router environments without centralized logging.