CVE-2018-10170 in NordVPN
Summary
by MITRE
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.
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Analysis
by VulDB Data Team • 01/25/2020
This vulnerability exists within NordVPN version 6.12.7.0 for Windows operating systems and represents a critical privilege escalation flaw that allows attackers to execute code with SYSTEM level privileges. The vulnerability stems from the nordvpn-service component which establishes a NetNamedPipe endpoint that exposes publicly accessible methods to any locally installed application. This service architecture creates an attack surface where unprivileged users can interact with privileged components through legitimate application installation paths. The specific flaw occurs within the Connect method which accepts a class instance argument, providing attackers with direct control over the OpenVPN command line parameters. This design flaw enables arbitrary code execution in the context of the SYSTEM user, effectively bypassing standard user permission boundaries and creating a severe security risk for all systems running the affected VPN client.
The technical implementation of this vulnerability follows a well-established pattern of privilege escalation through named pipe communication channels. The NetNamedPipe endpoint serves as a communication mechanism that allows local applications to interact with the privileged nordvpn-service. When an attacker invokes the Connect method with a specially crafted class instance, they gain control over the OpenVPN command line execution environment. This control extends to specifying dynamic library plugins that execute during each VPN connection attempt, creating a persistent execution environment with SYSTEM privileges. The vulnerability is classified under CWE-264 as a privilege escalation through improper access control, specifically manifesting as a weakness in the service architecture that fails to properly validate or restrict method invocation parameters. The flaw demonstrates poor security practices in service design where privileged operations are exposed without adequate authentication or authorization checks.
The operational impact of this vulnerability extends far beyond simple privilege escalation, creating a comprehensive attack vector that can be leveraged for persistent system compromise. Attackers can utilize this vulnerability to establish backdoors, exfiltrate sensitive data, modify system configurations, or deploy additional malware with elevated privileges. The persistent nature of the dynamic library plugin execution means that every new VPN connection attempt provides an opportunity for code execution, making this vulnerability particularly dangerous for long-running systems. The attack requires no special privileges initially, only the ability to run local applications, which makes it accessible to any user with basic system access. This vulnerability effectively neutralizes standard security boundaries and allows attackers to bypass typical user account controls, making it a significant concern for enterprise environments where system integrity is paramount.
Mitigation strategies for this vulnerability should focus on immediate service patching and architectural improvements to prevent similar issues in the future. Organizations should immediately update to NordVPN versions that address this privilege escalation vulnerability, as no reliable workarounds exist for the current implementation. The service architecture should be redesigned to eliminate the exposure of privileged methods through named pipes without proper authentication mechanisms. Security controls should include proper access control lists on named pipe endpoints and validation of all method parameters before execution. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and persistence mechanisms, specifically T1068 for local privilege escalation and T1078 for valid accounts. System administrators should monitor for unauthorized execution of the nordvpn-service and implement application whitelisting to prevent exploitation. Regular security audits of service architectures should be conducted to identify similar exposure patterns and ensure proper privilege separation between user and system components.