CVE-2025-13258
📋 TL;DR
A buffer overflow vulnerability in Tenda AC20 routers allows remote attackers to execute arbitrary code by manipulating the wpapsk_crypto parameter in the /goform/WifiExtraSet endpoint. This affects all Tenda AC20 routers running firmware version 16.03.08.12 or earlier. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Tenda AC20
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, creation of persistent backdoor, lateral movement to internal networks, and data exfiltration.
Likely Case
Router takeover enabling traffic interception, DNS hijacking, credential theft, and use as botnet node.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access, though internal network exposure remains.
🎯 Exploit Status
Public proof-of-concept exploit code is available, making exploitation trivial for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates
2. If update available, download and flash via web interface
3. Factory reset after update
4. Reconfigure with secure settings
🔧 Temporary Workarounds
Disable WAN Management
allPrevent remote access to router administration interface from internet
Network Segmentation
allIsolate router management interface to separate VLAN
🧯 If You Can't Patch
- Replace vulnerable router with supported model
- Place router behind firewall with strict inbound rules blocking all WAN access to management interfaces
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface at System Status > Firmware VersionCheck Version:
curl -s http://router-ip/goform/getStatus | grep versionVerify Fix Applied:
Verify firmware version is newer than 16.03.08.12📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/WifiExtraSet with long wpapsk_crypto parameter
- Unusual process creation or system reboots
Network Indicators:
- Unusual outbound connections from router
- Traffic to known exploit servers
- DNS queries to suspicious domains
SIEM Query:
source="router.log" AND (uri="/goform/WifiExtraSet" AND data_length>1000) OR (process="exploit" OR cmd="wget" OR cmd="curl")🔗 References
- https://github.com/DavCloudz/cve/blob/main/Tenda/Tengda%20AC20%20Router%20WifiExtraSet%20Buffer%20Overflow%20Vulnerability.md
- https://github.com/DavCloudz/cve/blob/main/Tenda/Tengda%20AC20%20Router%20WifiExtraSet%20Buffer%20Overflow%20Vulnerability.md#poc
- https://vuldb.com/?ctiid.332593
- https://vuldb.com/?id.332593
- https://vuldb.com/?submit.688716
- https://www.tenda.com.cn/
