NordVPN for Windows allows local attackers to stop unprotected Windows system services and change their startup type to Manual via named pipes. The NordVPN user-mode application allows a low-privileged attacker to act as a trusted process and connect to the named pipe "\\.\pipe\nord-security\v1\NordVpnService\Server". The attacker can then invoke the "ISettingsGrpc.StopService" and "ISettingsGrpc.ChangeServiceStartType" methods with an arbitrary service name, allowing them to stop any unprotected Windows service and change its startup type. This leads to denial of service of critical system services. Services protected by Windows (PPL processes, Windows Tamper Protection), such as Windows Defender, cannot be stopped or reconfigured.

This issue was fixed in version 8.12

NordVPN 6.19.6 contains a denial of service vulnerability that allows local attackers to crash the application by submitting an excessively long string in the email input field. Attackers can paste a buffer of 100,000 characters into the email field during login to trigger an application crash.

NordVPN 3.3.10 for macOS suffers from a root privilege escalation vulnerability. The vulnerability stems from its privileged helper tool's implemented XPC service. This XPC service is responsible for receiving and processing new OpenVPN connection requests from the main application. Unfortunately this XPC service is not protected, which allows arbitrary applications to connect and send it XPC messages. An attacker can send a crafted XPC message to the privileged helper tool requesting it make a new OpenVPN connection. Because he or she controls the contents of the XPC message, the attacker can specify the location of the openvpn executable, which could point to something malicious they control located on disk. Without validation of the openvpn executable, this will give the attacker code execution in the context of the privileged helper tool.

Nord VPN 6.31.13.0 contains an unquoted service path vulnerability in its nordvpn-service that allows local attackers to execute code with elevated privileges. Attackers can exploit the unquoted binary path during system startup or reboot to potentially run malicious code with LocalSystem permissions.

NordVPN 6.12.7.0 for Windows suffers from a SYSTEM privilege escalation vulnerability through the "nordvpn-service" service. This service establishes an NetNamedPipe endpoint that allows arbitrary installed applications to connect and call publicly exposed methods. The "Connect" method accepts a class instance argument that provides attacker control of the OpenVPN command line. An attacker can 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 user.

An exploitable code execution vulnerability exists in the connect functionality of NordVPN 6.14.28.0. A specially crafted configuration file can cause a privilege escalation, resulting in the execution of arbitrary commands with system privileges.