CVE-2024-30165: AWS Client VPN Buffer Overflow Vulnerability

CVE-2024-30165 Overview

CVE-2024-30165 is a buffer overflow vulnerability affecting Amazon AWS Client VPN versions prior to 3.9.1 on macOS. This security flaw could potentially allow a local actor to execute arbitrary commands with elevated permissions. The vulnerability is classified under CWE-120 (Buffer Copy without Checking Size of Input) and represents a distinct security issue from the related CVE-2024-30164.

Critical Impact

Local attackers with standard user privileges can exploit this buffer overflow to execute arbitrary commands with elevated permissions, potentially leading to full system compromise on affected macOS endpoints.

Affected Products

• Amazon AWS Client VPN for macOS versions prior to 3.9.1
• macOS systems running vulnerable AWS Client VPN installations
• Enterprise environments utilizing AWS Client VPN for remote connectivity

Discovery Timeline

• 2024-05-28 - CVE-2024-30165 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-30165

Vulnerability Analysis

This vulnerability stems from a classic buffer overflow condition in the AWS Client VPN application for macOS. Buffer overflows occur when a program writes data beyond the boundaries of allocated memory buffers, which can corrupt adjacent memory, alter program execution flow, or enable injection of malicious code.

The local attack vector requires an attacker to have some level of access to the target macOS system, but does not require user interaction to exploit. Once exploited, the vulnerability enables high-impact compromise of both confidentiality and integrity, potentially allowing attackers to access sensitive data and modify system configurations with elevated privileges.

Root Cause

The vulnerability is attributed to CWE-120: Buffer Copy without Checking Size of Input (Classic Buffer Overflow). This occurs when the application fails to properly validate the size of input data before copying it into a fixed-size buffer. In the context of the AWS Client VPN, insufficient bounds checking in memory operations creates conditions where carefully crafted input can overflow allocated buffers.

Attack Vector

The attack requires local access to a macOS system running a vulnerable version of AWS Client VPN. The attacker must have low-level privileges on the system to initiate the exploit. The exploitation does not require any user interaction, making it particularly dangerous in shared computing environments or scenarios where an attacker has gained initial foothold through other means.

The buffer overflow can be leveraged to overwrite critical memory structures, potentially including return addresses or function pointers, which can redirect program execution to attacker-controlled code running with the elevated permissions of the VPN client process.

For detailed technical information about the vulnerability mechanism, refer to the AWS Client VPN macOS Guide.

Detection Methods for CVE-2024-30165

Indicators of Compromise

• Unusual process behavior or crashes associated with AWS VPN Client processes on macOS
• Unexpected elevated process spawning from VPN client application contexts
• Anomalous memory access patterns or segmentation faults in VPN client logs
• Evidence of local privilege escalation attempts following VPN client activity

Detection Strategies

• Monitor for abnormal process execution chains originating from AWS VPN Client binaries
• Implement endpoint detection rules for buffer overflow exploitation patterns on macOS
• Deploy application integrity monitoring to detect tampering with VPN client components
• Use behavioral analysis to identify privilege escalation attempts following VPN client execution

Monitoring Recommendations

• Enable detailed logging for AWS Client VPN operations on macOS endpoints
• Configure SentinelOne agents to monitor for suspicious process injection or memory manipulation
• Establish baseline behavioral profiles for normal VPN client operations
• Implement real-time alerting for potential exploitation attempts targeting the VPN client

How to Mitigate CVE-2024-30165

Immediate Actions Required

• Upgrade AWS Client VPN to version 3.9.1 or later immediately on all macOS systems
• Conduct an inventory of all macOS endpoints to identify systems running vulnerable versions
• Implement application whitelisting to restrict execution to approved VPN client versions
• Review access controls to limit local user privileges where possible

Patch Information

Amazon has addressed this vulnerability in AWS Client VPN version 3.9.1 for macOS. Organizations should update their VPN clients to this version or later to remediate the vulnerability. The update can be obtained through standard AWS software distribution channels. Refer to the AWS Client VPN macOS Guide for download and installation instructions.

Workarounds

• Restrict local access to macOS systems running AWS Client VPN to trusted users only
• Implement network segmentation to limit the impact of potential compromise
• Deploy endpoint protection solutions capable of detecting buffer overflow exploitation attempts
• Consider temporarily disabling AWS Client VPN on non-essential systems until patching is complete

# Verify AWS Client VPN version on macOS
# Navigate to Applications and check VPN client info, or use:
defaults read /Applications/AWS\ VPN\ Client/AWS\ VPN\ Client.app/Contents/Info.plist CFBundleShortVersionString

# Ensure version is 3.9.1 or higher
# If vulnerable, download updated version from AWS documentation portal