CVE-2023-37575: Use-After-Free Vulnerabilities in GTKWave 3.3.115

Overview

In this post, we will be examining the CVE-2023-37575 vulnerability-a series of use-after-free vulnerabilities found in the VCD get_vartoken realloc functionality of GTKWave 3.3.115. This vulnerability is notable due to its ability to allow an attacker to execute arbitrary code on a system. The exploitation of this vulnerability requires a victim to open a maliciously crafted .vcd file, making it a potential threat to users and systems that handle .vcd files.
This vulnerability is significant not only because of the potential damage it can cause, but also because of its relative simplicity; it requires only user interaction for successful execution, making it a dangerous vector for attacks aiming to compromise systems or leak sensitive data.

Vulnerability Summary

CVE ID: CVE-2023-37575
Severity: High (CVSS: 7.8)
Attack Vector: Local
Privileges Required: None
User Interaction: Required
Impact: Potential system compromise and data leakage

Affected Products

Product | Affected Versions

GTKWave | 3.3.115

How the Exploit Works

The use-after-free vulnerabilities in the VCD get_vartoken realloc functionality of GTKWave 3.3.115 occur when the software uses a pointer after the system has freed the memory it points to. When a victim opens a specially crafted .vcd file, an attacker can manipulate the memory allocation to execute arbitrary code. This code execution can lead to a system compromise or potential data leakage, depending on the attacker’s intent.

Conceptual Example Code

Below is a conceptual example of how the vulnerability might be exploited. In this case, the attacker creates a malicious .vcd file that triggers the use-after-free vulnerability when opened.

# Pseudocode
Create malicious_vcd_file.vcd
{
Manipulate memory allocation via get_vartoken realloc function
Inject arbitrary malicious code
}
Send malicious_vcd_file.vcd to victim
{
Victim opens malicious_vcd_file.vcd
Arbitrary malicious code executes leading to potential system compromise or data leakage
}

Please note that this is a conceptual example and may not reflect the exact method an attacker might use to exploit this vulnerability. It is intended to illustrate the basic principle of the exploit and should not be used for malicious purposes.

Mitigation Guidance

To mitigate the risks associated with the CVE-2023-37575 vulnerability, users and administrators are advised to apply vendor patches as soon as they become available. In the absence of a patch, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure. These measures can protect against the arbitrary code execution that forms the basis of the exploit. However, they should serve only as an interim solution until a more permanent fix can be applied.