Security experts at the VPN provider Perfect Privacy discovered a new vulnerability dubbed Port Fail that could be exploited to de-anonymize VPN users. An attacker can exploit the Port Fail flaw to reveal the real IP-addresses of VPN users, including BitTorrent users. Experts at Perfect Privacy tested nine VPN providers out of which five were found to be vulnerable to the Port fail flaw, the providers Private Internet Access (PIA), Ovpnpn.to and nVPN have fixed the issue before publication.”]
Source: http://securityaffairs.co/wordpress/42322/hacking/port-fail-vpn-attack.html