Researchers have uncovered vulnerabilities in popular virtual private network (VPN) software, ProtonVPN and NordVPN, which can lead to the execution of arbitrary code by attackers. From a report: Last week, Cisco Talos security researchers said the security flaws, CVE-2018-3952 and CVE-2018-4010, permit code execution by attackers on Microsoft Windows machines. The vulnerabilities are similar to a Windows privilege escalation security flaw uncovered by VerSprite, which is tracked as CVE-2018-10169. Security patches were applied in April by both clients to resolve the original security hole, but according to Talos, “despite the fix, it is still possible to execute code as an administrator on the system.” The initial vulnerability was caused by similar design issues in both clients. The interface for both NordVPN and ProtonVPN execute binaries with the permission of a logged-in user, and this includes the selection of a VPN configuration option, such as a desired VPN server location. This information is sent to a service when “connect” is clicked by way of an OpenVPN configuration file. However, VerSprite was able to create a crafted OpenVPN file which could be sent to the service, loaded, and executed.