A critical stack-based buffer overflow in the Tenda CH22 router firmware allows remote attackers to achieve remote code execution or system disruption.

The vulnerability exists within the formCreateFileName function of the /goform/createFileName endpoint. By supplying a specially crafted fileNameMit parameter, an authenticated attacker can trigger a memory corruption event, leading to a stack-based buffer overflow.

Successful exploitation of this vulnerability poses a severe risk to organizational network security. As the flaw allows for remote code execution, an attacker could gain full control over the router, facilitating lateral movement within the internal network, traffic interception, or permanent denial of service. Given the CVSS score of 8.8, this vulnerability is categorized as high severity and requires immediate prioritization in security patching cycles.

Immediate Action: Check the official Tenda support portal for firmware updates addressing this vulnerability. If no patch is currently available for version 1.0.0.1, restrict administrative access to the device management interface to trusted internal segments only.

Proactive Monitoring: Monitor network traffic for unusual POST requests directed at the /goform/createFileName endpoint. Review system logs for unexpected crashes or service restarts that may indicate attempted exploitation.

Compensating Controls: If the device is exposed to the internet, immediately place the management interface behind a firewall or VPN to prevent remote access by unauthorized actors.

Public Exploit Available: Yes, a published proof-of-concept exists, as documented in the technical write-up provided by the vulnerability researcher.

The severity of this remote code execution vulnerability necessitates urgent action. Administrators should verify the current firmware version of all Tenda CH22 devices and apply vendor-supplied security patches as soon as they are released. Until a patch is verified and deployed, limiting access to the management interface is the most effective method to reduce the attack surface and prevent unauthorized exploitation.