CVE-2018-10169 in ProtonVPN
Summary
by MITRE
ProtonVPN 1.3.3 for Windows suffers from a SYSTEM privilege escalation vulnerability through the "ProtonVPN 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. This plugin will execute code in the context of the SYSTEM user.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/25/2020
The vulnerability identified as CVE-2018-10169 represents a critical privilege escalation flaw in ProtonVPN version 1.3.3 for Windows operating systems. This security weakness stems from the improper implementation of the ProtonVPN Service component which operates with elevated SYSTEM privileges. The service exposes a NetNamedPipe endpoint that creates an attack surface allowing any locally installed application to establish connections and invoke publicly accessible methods. This design flaw fundamentally violates the principle of least privilege by granting unnecessary access to system-level operations.
The technical exploitation mechanism centers on the "Connect" method within the ProtonVPN Service which accepts a class instance argument as input. This parameter provides attackers with direct control over the OpenVPN command line execution process. The vulnerability becomes particularly dangerous because it allows arbitrary dynamic library plugins to be specified and executed for every new VPN connection. When these malicious plugins are loaded, they execute within the SYSTEM user context, effectively granting attackers complete control over the compromised system. This represents a classic privilege escalation vector where a local user can elevate their privileges to the highest system level.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass full system compromise capabilities. Attackers who successfully exploit this flaw can execute arbitrary code with SYSTEM privileges, potentially leading to complete system takeover, data exfiltration, or persistence mechanisms establishment. The vulnerability affects any Windows system running ProtonVPN 1.3.3 where local applications can connect to the exposed NetNamedPipe endpoint. This makes it particularly concerning in enterprise environments where multiple applications might be installed and could potentially exploit this weakness.
Security professionals should note that this vulnerability aligns with CWE-269, which addresses improper privilege management, and represents a significant deviation from secure coding practices. The ATT&CK framework categorizes this as a privilege escalation technique under T1068, specifically targeting service execution and process injection methods. Organizations should implement immediate mitigations including updating to patched versions of ProtonVPN, restricting access to the NetNamedPipe endpoint, and monitoring for unauthorized connections to the ProtonVPN service. Additionally, system administrators should consider implementing application whitelisting policies to prevent arbitrary plugins from executing within the VPN context, thereby reducing the attack surface and protecting against similar vulnerabilities in the future.