The PureVPN client before 6.1.0 for Windows stores Login Credentials (username and password) in cleartext. The location of such files is %PROGRAMDATA%\purevpn\config\login.conf. Additionally, all local users can read this file.
PureVPN 6.0.1 for Windows suffers from a SYSTEM privilege escalation vulnerability in its "sevpnclient" service. When configured to use the OpenVPN protocol, the "sevpnclient" service executes "openvpn.exe" using the OpenVPN config file located at %PROGRAMDATA%\purevpn\config\config.ovpn. This file allows "Write" permissions to users in the "Everyone" group. An authenticated attacker may modify this file to specify a dynamic library plugin that should run for every new VPN connection attempt. This plugin will execute code in the context of the SYSTEM account.