CVE-2023-39272: Integer Overflow Vulnerability in GTKWave LXT2 Facgeometry Parsing

Overview

A critical vulnerability, identified as CVE-2023-39272, has been discovered in the LXT2 facgeometry parsing functionality of GTKWave version 3.3.115. This impacts any individual or organization using this version of GTKWave, a popular waveform viewer for viewing VCD/LXT, etc. The vulnerability relies on an integer overflow when allocating the `lsb` array, which could potentially be exploited leading to arbitrary code execution. Due to its severity and potential impact, it is crucial to understand the nature of this vulnerability and implement the necessary countermeasures.

Vulnerability Summary

CVE ID: CVE-2023-39272
Severity: High (7.8 CVSS Score)
Attack Vector: File-based
Privileges Required: None
User Interaction: Required
Impact: Arbitrary Code Execution, Potential System Compromise, Possible Data Leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The exploit revolves around the LXT2 facgeometry parsing functionality of GTKWave. The vulnerability arises due to an integer overflow when allocating the `lsb` array. An attacker can craft a malicious .lxt2 file that, when opened by the victim, triggers the overflow. This overflow can subsequently lead to arbitrary code execution. This means an attacker could potentially gain control over the system, compromising it or leading to data leakage.

Conceptual Example Code

Here’s a conceptual illustration of how the vulnerability might be exploited. This pseudocode demonstrates crafting a malicious .lxt2 file:

# Pseudocode for creating a malicious .lxt2 file
def create_malicious_file():
file = open("malicious.lxt2", "w")
# The data variable represents a specially crafted payload that triggers the integer overflow
data = generate_overflow_payload()
file.write(data)
file.close()
def generate_overflow_payload():
# This pseudocode function would generate a payload designed to trigger the integer overflow
# Note: this is a conceptual representation and may not directly correlate to real .lxt2 file structure or overflow exploit
return "overflow_triggering_data"

Prevention and Mitigation

To mitigate the risks associated with this vulnerability, the primary recommendation is to apply the vendor patch as soon as it is available. In the interim, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure, offering some level of protection against potential exploits.