CVE-2023-37921: Multiple Arbitrary Write Vulnerabilities in GTKWave 3.3.115

Overview

The Common Vulnerabilities and Exposures system has identified a critical vulnerability in GTKWave 3.3.115, a popular open-source software program for viewing digital timing waveforms. The vulnerability, designated CVE-2023-37921, involves multiple arbitrary write vulnerabilities in the VCD sorted bsearch functionality of GTKWave. If exploited, these vulnerabilities could allow an attacker to execute arbitrary code, potentially leading to system compromise or data leakage. It’s critical for users and administrators of systems running GTKWave 3.3.115 to understand and address this vulnerability to maintain the security and integrity of their systems.

Vulnerability Summary

CVE ID: CVE-2023-37921
Severity: High, CVSS score 7.8
Attack Vector: .vcd file
Privileges Required: User level
User Interaction: Required
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The exploit works by taking advantage of the VCD sorted bsearch functionality in GTKWave 3.3.115. An attacker crafts a malicious .vcd file, which when opened in the GTKWave software, triggers arbitrary write vulnerabilities. This allows the attacker to execute arbitrary code on the victim’s system. The vulnerability is triggered via the vcd2vzt conversion utility, which means that any user who opens the malicious file will inadvertently trigger the exploit.

Conceptual Example Code

Let’s assume that the malicious .vcd file contains a special payload designed to exploit this vulnerability. A pseudocode example of such a payload might look like this:

# malicious payload within .vcd file
payload = {
'command': 'arbitrary code here',
'trigger': 'vcd2vzt conversion utility'
}
# function to write the payload to a target file
def exploit(target_file, payload):
with open(target_file, 'w') as f:
f.write(payload)

This hypothetical payload, when processed by the vcd2vzt conversion utility within GTKWave, would trigger the arbitrary write vulnerabilities and execute the arbitrary code specified in the payload.

Remediation and Mitigation

The best course of action to protect against CVE-2023-37921 is to apply the vendor patch. As an interim measure before the patch is applied, or if the patch cannot be applied for some reason, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide a temporary mitigation against the exploit. However, these measures are not a substitute for patching and updating the software.