Amazon Web Services (AWS) has recently disclosed a significant security vulnerability in its Client VPN software for Windows, identified as CVE-2025-8069. This flaw allows non-administrative users to escalate their privileges, potentially executing malicious code with administrative rights. The vulnerability affects multiple versions of the AWS Client VPN client and has been addressed in the latest release.
Understanding the Vulnerability
The issue arises during the installation process of the AWS Client VPN client on Windows systems. Specifically, the installer references a fixed directory path: `C:\usr\local\windows-x86_64-openssl-localbuild\ssl` to access the OpenSSL configuration file. This predictable path creates a security loophole that malicious actors can exploit.
In this scenario, a non-administrative user can place arbitrary code within the OpenSSL configuration file located at the specified directory. If an administrator subsequently initiates the AWS Client VPN client installation, the embedded malicious code executes with root-level privileges. This escalation grants attackers the highest level of system access, enabling them to install malware, alter system settings, or access sensitive data.
Affected Versions and Platforms
The vulnerability impacts the following versions of AWS Client VPN for Windows:
– 4.1.0
– 5.0.0
– 5.0.1
– 5.0.2
– 5.1.0
– 5.2.0
– 5.2.1
Notably, this security flaw is specific to Windows devices. Installations on Linux and macOS platforms remain unaffected, indicating that the vulnerability is tied to Windows-specific implementation details in the installation process.
Discovery and Disclosure
The Zero Day Initiative discovered and reported this vulnerability through a coordinated disclosure process. This collaboration underscores the critical role of responsible security research in identifying and mitigating potential threats before they can be exploited maliciously.
Risk Assessment
The vulnerability has been assigned a Common Vulnerability Scoring System (CVSS) score of 7.8, categorizing it as a high-severity issue. The risk factors include:
– Affected Products: AWS Client VPN for Windows versions 4.1.0 through 5.2.1.
– Impact: Local privilege escalation.
– Exploit Prerequisites: A non-admin user must have write access to the specified directory, and an administrator must launch the AWS Client VPN installer.
Given these factors, the vulnerability poses a significant risk, especially in environments where multiple users have access to Windows systems running AWS Client VPN.
Mitigation and Recommendations
AWS has addressed this security vulnerability in AWS Client VPN Client version 5.2.2, which is now available for download. The company strongly recommends that organizations immediately discontinue new installations of any AWS Client VPN version prior to 5.2.2 on Windows systems to prevent potential exploitation.
System administrators should prioritize updating to the patched version, particularly in shared computing environments where untrusted users might have limited access to systems. The local privilege escalation nature of this vulnerability makes it especially concerning in such settings.
Steps to Update:
1. Download the Latest Version: Obtain AWS Client VPN Client version 5.2.2 from the official AWS website.
2. Uninstall Previous Versions: Remove any existing installations of AWS Client VPN versions 4.1.0 through 5.2.1 from Windows systems.
3. Install the Updated Version: Follow the installation instructions provided by AWS to install version 5.2.2.
4. Verify Installation: Ensure that the installation was successful and that the system is functioning correctly.
Conclusion
The disclosure of CVE-2025-8069 highlights the importance of maintaining up-to-date software to safeguard against potential security threats. Organizations using AWS Client VPN for Windows should act promptly to update their systems to version 5.2.2, thereby mitigating the risk associated with this vulnerability. Regularly monitoring for security updates and adhering to best practices in software maintenance are essential steps in protecting systems from emerging threats.
