CVE-2023-37577: Code Execution Vulnerability in GTKWave 3.3.115

Overview

The Common Vulnerabilities and Exposures (CVE) system has recently identified a high-severity vulnerability, CVE-2023-37577, in the popular GTKWave open-source waveform viewer version 3.3.115. This vulnerability, which involves multiple use-after-free issues, affects users who open specially crafted .vcd files and can lead to arbitrary code execution. Given the widespread use of waveform viewers in diverse industries such as electronics and software development, this vulnerability carries significant risk and warrants immediate attention.

Vulnerability Summary

CVE ID: CVE-2023-37577
Severity: High (CVSS 7.8)
Attack Vector: Opening a malicious .vcd file
Privileges Required: None
User Interaction: Required
Impact: Arbitrary code execution leading to potential system compromise or data leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The vulnerability exists in the VCD get_vartoken realloc functionality of GTKWave 3.3.115. When a user opens a specially crafted .vcd file, the program wrongly reallocates memory for certain objects, which can then be freed while still in use. This creates ‘dangling pointers,’ referencing memory that has been freed or reallocated. An attacker can exploit these use-after-free vulnerabilities to cause the program to execute arbitrary code, potentially compromising the system or leaking sensitive data.

Conceptual Example Code

Below is a conceptual representation of how the malicious .vcd file might be structured. This example is only intended to provide a high-level understanding of the exploit and is not a functioning exploit.

// Malicious .vcd file pseudocode
BEGIN_VCD
VERSION "GTKWave 3.3.115"
TIMESCALE 1ns
SCOPE module top
VAR wire 1 ! clk
VAR wire 1 " data
UPSCOPE
END
$dumpvars
0!
0"

In this example, the malicious .vcd file is crafted in a way that causes the VCD get_vartoken realloc functionality to create a use-after-free condition, which can then be exploited to execute arbitrary code.

Mitigation

Users are advised to apply the vendor patch as soon as it becomes available. Until then, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as temporary mitigation, potentially blocking or detecting attempts to exploit this vulnerability.