The VPN component in Windscribe 1.81 uses the OpenVPN client for connections. Also, it creates a WindScribeService.exe system process that establishes a \\.\pipe\WindscribeService named pipe endpoint that allows the Windscribe VPN process to connect and execute an OpenVPN process or other processes (like taskkill, etc.). There is no validation of the program name before constructing the lpCommandLine argument for a CreateProcess call. An attacker can run any malicious process with SYSTEM privileges through this named pipe.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.