CVE-2018-6822 in PureVPN
Summary
by MITRE
In PureVPN 6.0.1 on macOS, HelperTool LaunchDaemon implements an unprotected XPC service that can be abused to execute system commands as root.
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Analysis
by VulDB Data Team • 01/02/2020
The vulnerability identified as CVE-2018-6822 resides within PureVPN version 6.0.1 for macOS operating systems, specifically targeting the HelperTool LaunchDaemon component that manages an unprotected XPC service. This represents a critical privilege escalation flaw that allows unauthorized local users to execute arbitrary system commands with root privileges, fundamentally compromising the security model of the affected system.
The technical implementation of this vulnerability stems from the improper handling of XPC (Cross-Platform Communication) services within the PureVPN HelperTool. XPC services are designed to facilitate secure inter-process communication between privileged helper tools and user applications, but in this case, the service lacks proper authentication mechanisms and access controls. The unprotected XPC service creates an attack surface where malicious actors can send crafted XPC messages to the helper tool, bypassing normal security boundaries that should prevent unauthenticated command execution. This flaw directly maps to CWE-284, which addresses inadequate access control mechanisms, and specifically manifests as a weakness in privilege management where insufficient checks allow elevation to root privileges.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to perform arbitrary system modifications, install malicious software, modify system configurations, or exfiltrate sensitive data. The attack vector requires local access to the system but does not necessitate network connectivity or complex exploitation techniques, making it particularly dangerous in environments where physical access is possible. Once exploited, the attacker maintains persistent root access, allowing for complete system compromise and potential lateral movement within networked environments. This vulnerability directly aligns with ATT&CK technique T1068, which describes 'Exploitation for Privilege Escalation', and T1059, covering 'Command and Scripting Interpreter', as the compromised system can be used to execute commands and scripts with elevated privileges.
Mitigation strategies for CVE-2018-6822 should prioritize immediate patching of the PureVPN application to version 6.0.2 or later, which contains the necessary security fixes. System administrators should also implement monitoring for suspicious XPC service activity and consider disabling unnecessary helper tools when not actively in use. Network segmentation and access control policies should limit local system access to reduce the attack surface. Additionally, organizations should conduct regular security assessments to identify similar vulnerabilities in other third-party applications that may implement unprotected XPC services. The vulnerability highlights the importance of proper security testing for privileged helper tools and demonstrates how seemingly minor implementation flaws in system components can lead to complete system compromise.