Totolink A8000RU Command Injection Vulnerability in CGI Handler

A command injection vulnerability has been identified in the Totolink A8000RU router, specifically in version 7.1cu.643_b20200521. The issue resides within the CGI handler, in a function called setIptvCfg, located in the file cstecgi.cgi. This vulnerability allows remote attackers to execute arbitrary operating system commands by manipulating the igmpVer parameter in a crafted HTTP request. The injected commands are executed with root privileges, potentially compromising the router and the connected network.

Impact

Exploitation of this vulnerability allows for arbitrary command execution on the affected router with root privileges. This could lead to a complete compromise of the device and potentially the network it is connected to.

Reproduction

To reproduce this vulnerability, send a POST request to the /cgi-bin/cstecgi.cgi endpoint. Include the igmpVer parameter in the request body, and set its value to a command payload, such as ls>./setIptvCfg.txt. The router will execute the injected command and create a text file containing the command output.