CVE-2018-10190 in Private Internet Access
Summary
by MITRE
A vulnerability in London Trust Media Private Internet Access (PIA) VPN Client v77 for Windows could allow an unauthenticated, local attacker to run executable files with elevated privileges. The vulnerability is due to insufficient implementation of access controls. The "Changelog" and "Help" options available from the system tray context menu spawn an elevated instance of the user's default web browser. An attacker could exploit this vulnerability by selecting "Run as Administrator" from the context menu of an executable file within the file browser of the spawned default web browser. This may allow the attacker to execute privileged commands on the targeted system.
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Analysis
by VulDB Data Team • 01/25/2020
The vulnerability identified as CVE-2018-10190 resides within the London Trust Media Private Internet Access VPN client version 77 for Windows operating systems, representing a critical privilege escalation flaw that directly undermines the security posture of affected systems. This vulnerability stems from inadequate access control implementation within the application's graphical user interface components, specifically manifesting through the system tray context menu options that lack proper privilege verification mechanisms. The flaw operates on the fundamental principle that certain application functions should not be executable with elevated privileges without proper authentication and authorization checks, yet the PIA client fails to enforce these critical security boundaries.
The technical exploitation mechanism involves a chain of privilege escalation steps that begin with the attacker leveraging the vulnerable "Changelog" and "Help" options accessible through the system tray context menu. These options are designed to launch the user's default web browser in an elevated context, creating a dangerous execution path where the browser process runs with administrative privileges. This design flaw allows an attacker to manipulate the browser's execution environment through the Windows file browser interface, specifically targeting the "Run as Administrator" option that becomes available within the browser's file selection context. The vulnerability directly maps to CWE-276, which addresses improper privileges assigned to a component, and represents a classic case of insufficient privilege checking within application components that handle user interactions.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass full system compromise capabilities, as the elevated browser instance provides attackers with the ability to execute arbitrary code with administrative privileges. This presents a significant risk to enterprise environments where PIA clients are deployed, as it allows local attackers to bypass standard security controls and potentially establish persistent access to compromised systems. The attack vector is particularly concerning because it requires minimal user interaction beyond the initial exploitation of the system tray menu, making it difficult to detect and prevent through traditional security measures. The vulnerability also aligns with ATT&CK technique T1068, which describes the use of privilege escalation through local exploitation, and demonstrates how seemingly benign application features can be weaponized for malicious purposes.
Mitigation strategies for CVE-2018-10190 should focus on immediate patching of the PIA client to version 78 or later, which contains the necessary access control fixes to prevent unauthorized privilege escalation. Organizations should implement application whitelisting policies to restrict execution of unsigned or untrusted executables within the browser context, while also monitoring for suspicious process creation patterns that may indicate exploitation attempts. Network administrators should consider implementing additional security controls such as mandatory access controls and privilege separation mechanisms to limit the potential damage from such vulnerabilities. The vulnerability serves as a reminder of the critical importance of proper privilege management in application design and the necessity of thorough security testing for all user interface components, particularly those that interact with system-level functions or external applications. Regular security assessments and vulnerability scanning should include evaluation of application context menus and system tray interactions to identify similar privilege escalation vectors that may exist in other software components.