CVE-2023-35963: OS Command Injection Vulnerabilities in GTKWave

Overview

This blog post will delve into the details of the recently identified vulnerability, CVE-2023-35963, that affects the decompression functionality of GTKWave 3.3.115. GTKWave is a fully featured GTK+ based wave viewer that is used for viewing VCD waveform files. This vulnerability is particularly serious because its successful exploitation could lead to arbitrary command execution, and subsequently, a complete system compromise or data leakage. Cybersecurity professionals and organizations that use GTKWave should be aware and take appropriate measures to mitigate the risk associated with this vulnerability.

Vulnerability Summary

CVE ID: CVE-2023-35963
Severity: High (7.8 CVSS Score)
Attack Vector: Local
Privileges Required: Low
User Interaction: Required
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The vulnerability lies in the decompression functionality of GTKWave, specifically in the `vcd2lxt2` utility. Multiple OS command injection vulnerabilities exist, which, when exploited, can lead to the execution of arbitrary commands. An attacker would need to craft a malicious wave file and then trick the user into opening this file. Once the file is opened, the embedded commands in the wave file are executed, leading to the exploitation of the system.

Conceptual Example Code

Here is a conceptual example of how the vulnerability might be exploited:

# Create a malicious wave file
echo 'CMD_TO_EXECUTE' > malicious_wave.vcd
# Get victim to open the file in GTKWave
GTKWave malicious_wave.vcd

In this example, “CMD_TO_EXECUTE” is a placeholder for any command that an attacker wishes to execute on the victim’s system.

Steps to Mitigate

The best way to mitigate this vulnerability is to apply the vendor patch as soon as it becomes available. However, until then, users can use a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure. These tools can help detect and prevent the injection of malicious commands. Additionally, users should also practice caution when opening wave files from untrusted or unknown sources.