Overview
The Common Vulnerabilities and Exposures (CVE) system has identified an out-of-bounds write vulnerability in the VZT LZMA_read_varint function of GTKWave version 3.3.115. This vulnerability, designated as CVE-2023-36861, is particularly severe as it can potentially lead to arbitrary code execution. What this means is that an attacker could take control of the affected system, compromising its integrity and confidentiality. The vulnerability impacts any system running the affected version of GTKWave, which is widely used for viewing waveforms from digital circuits.
Vulnerability Summary
CVE ID: CVE-2023-36861
Severity: High (7.8 CVSS Score)
Attack Vector: .vzt file
Privileges Required: None
User Interaction: Required
Impact: Potential system compromise and data leakage.
Affected Products
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Product | Affected Versions
GTKWave | 3.3.115
How the Exploit Works
The vulnerability lies within the VZT LZMA_read_varint functionality of GTKWave. An attacker can exploit this vulnerability by crafting a malicious .vzt file. When this file is opened by a victim in GTKWave, it triggers an out-of-bounds write error. This error can then be leveraged to execute arbitrary code on the victim’s system. The exact technical details of this process can vary depending on the specific implementation of the exploit, but the general method involves manipulating the data within the .vzt file in such a way that it causes the program to write to an unintended memory location.
Conceptual Example Code
Below is a simplified conceptual example of how the vulnerability could be exploited. This pseudocode demonstrates how a .vzt file could be maliciously crafted:
# Pseudocode for crafting a malicious .vzt file
file = open("malicious.vzt", "wb")
# Write data to the file that will trigger an out-of-bounds write in GTKWave
file.write(b'crafted_data_that_causes_out_of_bounds_write')
# Write the arbitrary code that will be executed
file.write(b'arbitrary_code_to_execute')
file.close()It should be noted that the actual exploit would be much more complex and require a deep understanding of the GTKWave software and the system it is running on.
Mitigation Guidance
To mitigate this vulnerability, users of GTKWave should apply the vendor-released patch as soon as possible. If that is not immediately possible, temporary mitigation can be achieved by using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) to filter out malicious .vzt files. However, these measures should not be relied upon as a long-term solution. They are only meant to provide temporary relief until the official patch can be applied.