Oh-Pwn-VPN! Security Analysis of OpenVPN-Based Android Apps

Free VPN apps have gained popularity among millions of users due to their convenience, and have been massively used for accessing blocked sites and preventing network eavesdropping. As a popular open-source VPN solution, OpenVPN is widely used by developers to implement their own VPN services. Despite the prevalence of OpenVPN, it can be insecurely customized and deployed by developers in lack of security guide.