CVE-2023-35956 Explained : Impact and Mitigation

This article provides detailed information about CVE-2023-35956, a vulnerability found in GTKWave 3.3.115 that allows attackers to execute arbitrary code through specially-crafted .fst files.

Understanding CVE-2023-35956

This section delves into the nature of the vulnerability and its impact.

What is CVE-2023-35956?

The CVE-2023-35956 vulnerability involves multiple heap-based buffer overflow vulnerabilities in the fstReaderIterBlocks2 VCDATA parsing functionality of GTKWave 3.3.115. It can result in arbitrary code execution when a victim opens a malicious .fst file, triggering the vulnerabilities. The decompression function

fastlz_decompress

is a key concern in this vulnerability.

The Impact of CVE-2023-35956

The impact of this vulnerability is severe, with a CVSS base score of 7.8 (High). It has a local attack vector, low attack complexity, and requires user interaction. The confidentiality, integrity, and availability of the affected systems are all at high risk.

Technical Details of CVE-2023-35956

This section provides specific technical details about the vulnerability.

Vulnerability Description

The vulnerability stems from improper restriction of operations within the bounds of a memory buffer, classified under CWE-119.

Affected Systems and Versions

The vulnerability affects GTKWave version 3.3.115.

Exploitation Mechanism

A specially-crafted .fst file can trigger the vulnerability, leading to arbitrary code execution.

Mitigation and Prevention

To address and prevent exploitation of CVE-2023-35956, follow the below steps.

Immediate Steps to Take

Update GTKWave to a patched version that addresses the buffer overflow vulnerabilities.
Avoid opening suspicious or untrusted .fst files.

Long-Term Security Practices

Regularly update software and apply security patches promptly.
Implement least privilege access controls to limit the impact of potential attacks.

Patching and Updates

Stay informed about security updates for GTKWave and apply them as soon as they are available.