Critical macOS Privilege Escalation Found in AWS Client VPN

A critical local privilege escalation vulnerability has been discovered in the AWS Client VPN macOS client, potentially allowing non-administrator users to gain root privileges on affected systems.

Tracked as CVE-2025-11462 and published by AWS on October 7, 2025, this flaw stems from improper validation during log rotation and impacts AWS Client VPN Client versions 1.3.2 through 5.2.0.

Proper Validation Bypass in Log Rotation

AWS Client VPN is a managed, client-based VPN service offering secure remote access to AWS and on-premises resources across Windows, macOS, and Linux platforms.

AWS released Bulletin ID AWS-2025-020 describing CVE-2025-11462, which affects only the macOS client.

A lack of validation checks on the log destination directory allows a malicious user to create a symbolic link from the client log file to any privileged location.

By invoking an internal API with arbitrary inputs and then triggering log rotation, the attacker can write those inputs to the privileged path.

If the attacker links the log target to, for example, the system crontab file, cron jobs containing attacker-controlled entries will execute with root privileges.

Impact Assessment and Exploit Prerequisites

Exploitation of this vulnerability does not require the attacker to have administrator credentials, only a standard user session on the macOS endpoint.

The bug does not affect Windows or Linux AWS Client VPN clients. Successful exploitation yields full root privileges, enabling installation of persistent backdoors, tampering with system configurations, or disabling security protections.

Although no in-the-wild attacks have been reported at the time of disclosure, the severity and low complexity of the exploitation vector make rapid remediation imperative.

AWS has addressed the issue in AWS Client VPN Client version 5.2.1. Users running any macOS client version earlier than 5.2.1 must upgrade immediately to eliminate the privilege escalation vector.

No viable workarounds exist, and continued use of vulnerable versions leaves systems exposed to local compromise.

Below is a summary table of the vulnerability:

CVE ID	Affected Products	Impact	Exploit Prerequisites	CVSS 3.1 Score
CVE-2025-11462	AWS Client VPN Client for macOS 1.3.2–5.2.0	Local root privilege escalation	Non-admin user on macOS	7.8

Proof-of-concept exploitation involves creating a symlink from the client’s rotating log file to a privileged target (e.g., /etc/crontab), then calling the AWS Client VPN API to write attacker-controlled content into the crontab.

Finally, waiting for the scheduled log rotation causes cron to pick up and execute the injected entries as root.

Systems running the AWS Client VPN macOS client should verify their client version by opening the application’s “About” dialog or running the command-line tool with --version.

Immediate upgrade to version 5.2.1 is the only effective mitigation. Monitoring for unusual cron job entries and ensuring endpoint security solutions detect suspicious file system link creation can help detect exploitation attempts.

Continuous vigilance and prompt patch application remain essential to secure macOS endpoints against this critical vulnerability.

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