CVE-2025-11297
📋 TL;DR
A buffer overflow vulnerability in Belkin F9K1015 routers allows remote attackers to execute arbitrary code by manipulating the webpage argument in the /goform/formSetLanguage endpoint. This affects users of Belkin F9K1015 routers running firmware version 1.00.10. The vulnerability is remotely exploitable and a public proof-of-concept exists.
💻 Affected Systems
- Belkin F9K1015 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, network infiltration, and potential lateral movement to other devices.
Likely Case
Remote code execution allowing attackers to install malware, create backdoors, or use the device as part of a botnet.
If Mitigated
Denial of service or limited impact if proper network segmentation and access controls are implemented.
🎯 Exploit Status
Proof-of-concept exploit code is publicly available on GitHub. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
No official patch is available. Contact Belkin support for firmware updates. If an update becomes available: 1. Download firmware from Belkin website 2. Access router admin interface 3. Navigate to firmware update section 4. Upload and apply update 5. Reboot router
🔧 Temporary Workarounds
Block access to vulnerable endpoint
linuxUse firewall rules to block external access to /goform/formSetLanguage endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "/goform/formSetLanguage" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "/goform/formSetLanguage" --algo bm -j DROP
Disable remote administration
allTurn off remote management features in router settings
🧯 If You Can't Patch
- Segment affected routers in isolated network zones with strict firewall rules
- Implement network monitoring and intrusion detection for exploit attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface. If version is 1.00.10, device is vulnerable.Check Version:
curl -s http://router-ip/status.cgi | grep firmwareVerify Fix Applied:
Verify firmware version has changed from 1.00.10. Test if /goform/formSetLanguage endpoint still responds to buffer overflow attempts.📡 Detection & Monitoring
Log Indicators:
- Multiple requests to /goform/formSetLanguage with long parameter values
- Unusual process execution or memory errors in router logs
Network Indicators:
- HTTP requests to /goform/formSetLanguage with unusually long webpage parameters
- Traffic patterns suggesting buffer overflow attempts
SIEM Query:
source="router_logs" AND uri="/goform/formSetLanguage" AND (param_length>1000 OR contains(param,"AAAAAAAA"))🔗 References
- https://github.com/panda666-888/vuls/blob/main/belkin/f9k1015/formSetLanguage.md
- https://github.com/panda666-888/vuls/blob/main/belkin/f9k1015/formSetLanguage.md#poc
- https://vuldb.com/?ctiid.327178
- https://vuldb.com/?id.327178
- https://vuldb.com/?submit.661301
- https://github.com/panda666-888/vuls/blob/main/belkin/f9k1015/formSetLanguage.md
- https://github.com/panda666-888/vuls/blob/main/belkin/f9k1015/formSetLanguage.md#poc
