CVE-2025-15217
📋 TL;DR
A buffer overflow vulnerability in Tenda AC23 routers allows remote attackers to execute arbitrary code by sending specially crafted HTTP POST requests to the formSetPPTPUserList function. This affects Tenda AC23 routers running firmware version 16.03.07.52. Attackers can exploit this without authentication from the network.
💻 Affected Systems
- Tenda AC23
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete router compromise, credential theft, network pivoting, and persistent backdoor installation.
Likely Case
Router takeover enabling traffic interception, DNS manipulation, and network disruption.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access and strong network segmentation.
🎯 Exploit Status
Public technical details available; buffer overflow manipulation of 'list' argument enables remote exploitation.
🛠️ 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. Access router admin interface 4. Upload and apply firmware update 5. Reboot router
🔧 Temporary Workarounds
Disable Remote Management
allDisable WAN access to router administration interface
Access router admin > Advanced > System > Remote Management > Disable
Network Segmentation
linuxPlace router behind firewall with restricted inbound access
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Replace affected Tenda AC23 router with different model or vendor
- Implement strict network ACLs to block all inbound traffic to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface: System Status > Firmware VersionCheck Version:
curl -s http://router-ip/status.cgi | grep versionVerify Fix Applied:
Verify firmware version is newer than 16.03.07.52 after update📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to formSetPPTPUserList endpoint
- Multiple failed buffer overflow attempts in router logs
- Unexpected router reboots or crashes
Network Indicators:
- HTTP POST requests with oversized 'list' parameter to router IP
- Traffic patterns suggesting router compromise (unusual outbound connections)
SIEM Query:
source="router.log" AND "formSetPPTPUserList" AND (POST OR buffer)🔗 References
- https://lavender-bicycle-a5a.notion.site/Tenda-AC23-formSetPPTPUserList-2d753a41781f8091b772cf9e66a687f1?source=copy_link
- https://vuldb.com/?ctiid.338602
- https://vuldb.com/?id.338602
- https://vuldb.com/?submit.725448
- https://www.tenda.com.cn/
- https://lavender-bicycle-a5a.notion.site/Tenda-AC23-formSetPPTPUserList-2d753a41781f8091b772cf9e66a687f1
