CVE-2023-37417: Critical Out-of-Bounds Write Vulnerabilities in GTKWave 3.3.115

Overview

In the world of cybersecurity, there are unfortunately constant threats that users must guard against. CVE-2023-37417 is one such vulnerability that presents a potent risk to users of the GTKWave 3.3.115. This vulnerability exposes users to potential system compromise, data leakage, and arbitrary code execution risks, making it a critical issue that needs immediate attention.
GTKWave is a popular open-source waveform viewer, largely utilized in the digital design field. The vulnerability in question affects the VCD parse_valuechange portdump functionality, allowing malicious individuals the ability to execute arbitrary code, potentially compromising the entire system and leading to data leaks. The severity of this issue cannot be overstated, given its potential for widespread damage.

Vulnerability Summary

CVE ID: CVE-2023-37417
Severity: High – CVSS Score 7.8
Attack Vector: Remote
Privileges Required: None
User Interaction: Required
Impact: Arbitrary code execution, potential system compromise and data leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

This vulnerability takes advantage of an out-of-bound write condition in the VCD parse_valuechange portdump functionality of GTKWave 3.3.115. An attacker would need to craft a malicious .vcd file, designed to trigger the vulnerability. Once the malicious file is opened by the victim through the GUI’s interactive VCD parsing code, the attacker gains the ability to execute arbitrary code on the system, potentially leading to a full system compromise.

Conceptual Example Code

The following is a conceptual example of a malicious .vcd file content, designed to exploit the vulnerability:

$timescale 1 ns $end
$scope module logic $end
$var wire 1 ! clk $end
$var wire 64 # data $end
$var wire 1 $ en $end
$upscope $end
$enddefinitions $end
#0
0!
bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx #
1$

In the above example, the “bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx #” string represents an oversize binary value, specifically crafted to trigger the out-of-bound write condition, leading to arbitrary code execution.

Mitigation Guidance

Users are advised to apply the patch provided by the vendor as soon as possible. In the absence of a patch, or as a temporary mitigation measure, deploying a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can help to detect and prevent exploitation of this vulnerability. It is also strongly recommended that users avoid opening .vcd files from untrusted sources.