CVE-2023-37442: Severe Out-of-Bounds Read Vulnerabilities in GTKWave 3.3.115

Overview

The open-source waveform viewer, GTKWave 3.3.115, has been found to contain multiple severe out-of-bounds read vulnerabilities. These flaws, identified as CVE-2023-37442, can lead to arbitrary code execution, thus potentially compromising the system or leading to data leakage. The affected software is widely used for viewing Verilog, VHDL, and other simulation output formats, making this a pressing concern for developers and organizations alike. Mitigation efforts are underway, and immediate action is advised.

Vulnerability Summary

CVE ID: CVE-2023-37442
Severity: High (7.8 CVSS Score)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: System compromise and potential data leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The vulnerabilities specifically exist in the VCD var definition section of GTKWave. When a specially crafted .vcd file is opened by a user, it triggers an out-of-bounds read, leading to arbitrary code execution. This vulnerability is triggered via the GUI’s default VCD parsing code. This means that an attacker can craft a malicious .vcd file that, when opened, executes the attacker’s arbitrary code on the victim’s system.

Conceptual Example Code

A conceptual example of this vulnerability would involve the creation of a malicious .vcd file. While the specifics of such a file are beyond the scope of this article, the pseudo-code below illustrates the potential structure of such a file:

$scope module malicious $end
$var wire 1 ! trigger $end
$var wire 128 # payload $end
$upscope $end
$enddefinitions $end
#0
$dumpvars
1!
b{malicious_payload} #
$end

In this pseudo-code, ‘`malicious_payload`’ represents the arbitrary code that the attacker wishes to execute on the victim’s machine. The out-of-bounds read is triggered when GTKWave attempts to parse this malicious .vcd file, leading to the execution of the arbitrary code.

Mitigation Guidance

Users are advised to apply the vendor patch as soon as it becomes available. In the meantime, employing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation against potential exploits. It’s recommended to refrain from opening .vcd files from untrusted sources until the patch is applied.