Executive brief
A security vulnerability exists in the Comfast CF-WR631AX V3 wireless router, a device used for providing network connectivity. An attacker can exploit a flaw in the router's diagnostic tools to run unauthorized commands on the device. If successful, this could allow an attacker to take full control of the router, potentially leading to the interception of network traffic or a complete service outage.
Technical details
An OS command injection vulnerability exists in the Comfast CF-WR631AX V3 router (firmware up to V2.7.0.8) within the /usr/bin/webmgnt binary. The flaw is located in the handler for the /cgi-bin/mbox-config?section=ping_config API endpoint. The application uses blobmsg_parse_0 to extract the 'destination' parameter from a JSON POST body but fails to sanitize the input before passing it to sprintf and subsequently the system() function. By injecting shell metacharacters (e.g., \"; <command>; #) into the destination field, an authenticated attacker can achieve remote code execution with root privileges. As of the advisory date, the vendor has not responded to disclosure attempts and no patch is available.
Affected products
- Comfast CF-WR631AX V3 up to 2.7.0.8
Timeline
- 2026-06-21: advisory: Initial disclosure by VulDB
- 2026-06-21: disclosed: Public exploit analysis report released on GitHub