Executive brief
A security vulnerability exists in the Tenda AC8V4 wireless router, a device used to provide home and small office internet connectivity. An attacker can send a specially crafted request to the router's guest Wi-Fi settings page to cause the device to crash or become unresponsive. This could lead to a loss of internet connectivity for users relying on the router.
Technical details
A stack-based buffer overflow (CWE-121) exists in the Tenda AC8V4 router firmware version V16.03.34.06. The vulnerability is located within the 'fromSetWifiGusetBasic' function, which processes POST requests to the '/goform/WifiGuestSet' endpoint. The 'shareSpeed' parameter is retrieved from the user request without length validation and is subsequently passed to a 'strcpy' function, leading to a stack overflow. A remote, unauthenticated attacker can exploit this by sending a long string in the 'shareSpeed' field, potentially causing a denial-of-service (DoS) condition. A proof-of-concept exploit using a 2000-byte payload has been publicly disclosed.
Affected products
- Tenda AC8V4 V16.03.34.06
Timeline
- 2025-07-24: advisory: Initial NVD publication
- 2025-07-24: disclosed: Public GitHub advisory and PoC released