(Pwn2Own) Cisco RV340 upload.cgi JSON Command Injection Privilege Escalation Vulnerability

This vulnerability allows network-adjacent attackers to escalate privileges on affected installations of Cisco RV340 routers. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the handling of POST request parameters provided to the upload.cgi endpoint. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the www-data user.