CVE-2023-7224: OpenVPN Connect Vulnerability in macOS Versions 3.0 to 3.4.6

Overview

A substantial vulnerability, identified as CVE-2023-7224, has been discovered in OpenVPN Connect ranging from versions 3.0 through 3.4.6 on macOS. This vulnerability can potentially allow local users to execute code in external third-party libraries using the DYLD_INSERT_LIBRARIES environment variable. OpenVPN Connect, being a popular virtual private network (VPN) solution, is widely used for secure point-to-point or site-to-site connections. Therefore, this vulnerability poses a significant risk to the confidentiality and integrity of users’ data and systems.

Vulnerability Summary

CVE ID: CVE-2023-7224
Severity: High (CVSS: 7.8)
Attack Vector: Local
Privileges Required: Low
User Interaction: None
Impact: System Compromise, Potential Data Leakage

Affected Products

Product | Affected Versions

OpenVPN Connect | 3.0 through 3.4.6

How the Exploit Works

The exploit takes advantage of a flaw in OpenVPN Connect’s handling of environment variables, specifically the DYLD_INSERT_LIBRARIES variable. This variable is used in macOS to specify additional dynamic libraries to load before the ones specified in the application. An attacker with local access to the machine can manipulate this environment variable to point to a malicious library, which can then be loaded before the legitimate ones. Consequently, this could lead to arbitrary code execution in the context of the application, leading to a potential system compromise or data leakage.

Conceptual Example Code

An attacker might exploit the vulnerability with a shell command like this:

# Set the DYLD_INSERT_LIBRARIES environment variable to point to the malicious library
export DYLD_INSERT_LIBRARIES=/path/to/malicious/library.dylib
# Run OpenVPN Connect, which will now load the malicious library
open /Applications/OpenVPN\ Connect.app

Please note, this is a conceptual example and is not intended to be run verbatim. It is provided to illustrate the general method an attacker might use, not to provide a working exploit.

Mitigation Guidance

The primary mitigation for this vulnerability is to apply the vendor patch as soon as possible. If immediate patching isn’t feasible, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as a temporary mitigation. These can be configured to monitor and block suspicious activity that could be associated with this exploit. As always, ensure that your systems are updated regularly and follow best practices for secure coding and configuration.