CVE-2023-35970: Heap-Based Buffer Overflow Vulnerability in GTKWave

Overview

In the ever-evolving landscape of cybersecurity, a new threat has emerged, identified as CVE-2023-35970. This vulnerability impacts the GTKWave 3.3.115 software package, widely used for viewing electronic timing diagrams. This vulnerability has serious implications as it can potentially allow an attacker to execute arbitrary code, leading to system compromise or data leakage. It is crucial for organizations using this package to be aware of this vulnerability and take immediate steps to mitigate it.

Vulnerability Summary

CVE ID: CVE-2023-35970
Severity: High – CVSS 7.8
Attack Vector: Local
Privileges Required: Low
User Interaction: Required
Impact: System compromise and potential data leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The vulnerability lies in the heap-based buffer overflow within the fstReaderIterBlocks2 chain_table parsing functionality of GTKWave. An attacker can craft a malicious .fst file, which when opened by the victim, can lead to arbitrary code execution. The issue arises from the chain_table of the `FST_BL_VCDATA_DYN_ALIAS2` section type, where a failure to properly validate and handle the malicious file can trigger these vulnerabilities.

Conceptual Example Code

This is a conceptual example of how the vulnerability might be exploited using a maliciously crafted .fst file:

#include <stdio.h>
#include <stdlib.h>
int main() {
FILE *file;
file = fopen("malicious.fst", "w");
if (file == NULL) {
printf("Error opening file\n");
return 1;
}
// Write data that exploits the buffer overflow vulnerability
fprintf(file, "malicious_payload");
fclose(file);
return 0;
}

This example demonstrates how an attacker might create a malicious .fst file. When this file is opened by GTKWave, it exploits the buffer overflow vulnerability, potentially leading to arbitrary code execution.

Mitigation

To mitigate this vulnerability, it is recommended 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 a temporary mitigation, helping to detect and prevent any attempted exploitation of this vulnerability. Additionally, organizations should enforce a strong security policy that includes not opening files from untrusted sources.