CVE-2023-39316: Integer Overflow in GTKWave’s LXT2 num_dict_entries Functionality

Overview

The Common Vulnerabilities and Exposures (CVE) system has recently documented a critical security vulnerability, identified as CVE-2023-39316, affecting the GTKWave software version 3.3.115. This vulnerability is related to multiple integer overflow issues existing in the LXT2 num_dict_entries functionality of the software. GTKWave is a fully featured GTK+ based wave viewer that has a wide user base, including system developers and administrators.
The vulnerability is of significant importance due to its potential to allow an attacker to execute arbitrary code, which could compromise the entire system or lead to data leakage. The successful exploitation of this vulnerability requires a user to open a malicious .lxt2 file that triggers these vulnerabilities.

Vulnerability Summary

CVE ID: CVE-2023-39316
Severity: High (7.8)
Attack Vector: Local File
Privileges Required: User level
User Interaction: Required
Impact: Potential system compromise, data leakage, and arbitrary code execution

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The vulnerability stems from an integer overflow in the allocation of the `string_pointers` array within the LXT2 num_dict_entries functionality of GTKWave. An attacker can craft a malicious .lxt2 file with specific properties that, when opened by the GTKWave software, causes an integer overflow. This overflow can then lead to arbitrary code execution, as insufficient bounds checking allows the attacker to write and execute malicious code in memory locations that should be inaccessible.

Conceptual Example Code

The following pseudocode conceptually illustrates the exploitation of this vulnerability:

#include <stdio.h>
#include <stdlib.h>
int main() {
// Create a malicious .lxt2 file
FILE *file;
file = fopen("malicious.lxt2", "w");
// Write malicious data that triggers integer overflow in the string_pointers array
for (int i=0; i<MAX_INT; i++) {
fwrite("\x00\x00\x00\x00", 4, 1, file);
}
// Close the file
fclose(file);
return 0;
}

Mitigation

Users of GTKWave 3.3.115 are encouraged to apply the vendor-supplied patch as soon as it is available. In the meantime, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can help detect and prevent the successful exploitation of this vulnerability. Regularly updating all software and maintaining a robust cyber hygiene practice can also minimize the risk of similar vulnerabilities.