CVE-2018-3952 in NordVPN
Summary
by MITRE
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.
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Analysis
by VulDB Data Team • 03/21/2020
The vulnerability identified as CVE-2018-3952 represents a critical privilege escalation flaw within NordVPN version 6.14.28.0 that allows attackers to execute arbitrary commands with system-level privileges. This issue specifically affects the application's connect functionality and stems from improper handling of configuration files during the connection process. The vulnerability manifests when a maliciously crafted configuration file is processed by the application, leading to unauthorized privilege elevation that can result in complete system compromise.
The technical root cause of this vulnerability lies in insufficient input validation and sanitization within the NordVPN client's configuration file parsing mechanism. When the application processes configuration files, it fails to properly validate the contents of these files before executing any commands or operations derived from them. This weakness creates a path for attackers to inject malicious code that gets executed with elevated privileges. The flaw essentially allows a local attacker to manipulate the application's behavior through crafted input, bypassing normal security boundaries that should prevent privilege escalation. This type of vulnerability aligns with CWE-78 and CWE-79, which address improper input validation and command injection flaws respectively, both of which are fundamental security weaknesses in software development practices.
The operational impact of CVE-2018-3952 extends far beyond simple privilege escalation, as it provides attackers with complete system control capabilities. Once exploited, the vulnerability enables unauthorized users to execute arbitrary commands with system privileges, potentially allowing them to install malware, modify system files, access sensitive data, or establish persistent backdoors. The attack vector requires local system access and the ability to manipulate configuration files, making it particularly concerning for environments where users might have limited access but could potentially interact with the application's configuration management. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under privilege escalation and command and control categories, specifically targeting the execution of malicious code with elevated permissions.
Mitigation strategies for CVE-2018-3952 should prioritize immediate software updates to the latest stable version of NordVPN where the vulnerability has been patched. System administrators should implement strict file access controls and monitoring for configuration files to prevent unauthorized modifications. The application should be configured to run with minimal required privileges and employ proper input validation techniques to sanitize all configuration file contents before processing. Additional defensive measures include implementing application whitelisting, monitoring for suspicious command execution patterns, and conducting regular security assessments of the application's configuration handling mechanisms. Organizations should also consider network segmentation and monitoring to detect potential exploitation attempts, as the vulnerability requires local system access to be effectively exploited. The patching process should be prioritized in environments where system integrity is paramount, and comprehensive testing should be performed to ensure that the update does not introduce regressions in legitimate functionality.