Security researcher Guido Vranken of Netherlands exclusively used a fuzzer and recently discovered four security holes in OpenVPN that escaped both the security audits of the open source VPN software. Three of the four flaws the researcher discovered are server-side, two of which cause servers to crash, while the remaining is a client-side bug that could allow an attacker to steal a password to gain access to the proxy. The team has already patched the issues in its latest version of the VPN software.
Source: https://thehackernews.com/2017/06/openvpn-security-flaw_21.html