Executive brief
A security vulnerability exists in the Tenda F1202 wireless router, a device used to provide internet connectivity in homes and small offices. An attacker can exploit this flaw to crash the router or potentially take full control of the device. This could lead to a complete loss of internet access or allow an unauthorized person to monitor network traffic and access sensitive data.
Technical details
A stack-based buffer overflow vulnerability exists in the 'httpd' binary of the Tenda F1202 router, specifically within the 'formWrlExtraSet' function in '/goform/WrlExtraSet'. The vulnerability is caused by a lack of length validation on user-supplied parameters (identified as 'delno' or 'GO') before they are processed by functions like 'sprintf'. A remote attacker with low privileges can exploit this by sending a specially crafted POST request containing an overly long string. Successful exploitation can lead to a crash of the web service (Denial of Service) or potentially remote code execution (RCE). A public exploit (PoC) is available.
Affected products
- Tenda F1202 1.2.0.20(408)
Timeline
- 2026-05-25: disclosed: Vulnerability disclosed via VulDB and GitHub PoC
- 2026-05-25: advisory: CVE-2026-9429 published