Executive brief
A security vulnerability has been identified in the Tenda CX12L router, a device used to provide wireless internet connectivity. An attacker can exploit this flaw to crash the router's management interface or potentially take full control of the device. This could lead to unauthorized monitoring of network traffic, service outages, or the use of the router as a stepping stone to attack other devices on the home or business network.
Technical details
A stack-based buffer overflow vulnerability exists in the Tenda CX12L router firmware version 16.03.53.12. The flaw is located within the 'fromNatStaticSetting' function in the '/goform/NatStaticSetting' component. The root cause is the unsafe use of 'sprintf' when processing the user-controlled 'page' parameter, which is written into a fixed-size 256-byte buffer without length validation. A remote attacker can trigger this overflow by sending a specially crafted POST request with an oversized 'page' argument. Successful exploitation can lead to memory corruption, denial of service (DoS), or arbitrary code execution. A public proof-of-concept (PoC) exploit has been disclosed.
Affected products
- Tenda CX12L Router 16.03.53.12
Timeline
- 2026-03-30: disclosed: Vulnerability details and PoC shared on GitHub.
- 2026-04-06: advisory: Initial NVD publication.