CVE-2023-37576 in GTKWave
Summary
by MITRE • 01/08/2024
Multiple use-after-free vulnerabilities exist in the VCD get_vartoken realloc functionality of GTKWave 3.3.115. A specially crafted .vcd file can lead to arbitrary code execution. A victim would need to open a malicious file to trigger these vulnerabilities.This vulnerability concerns the use-after-free when triggered via the vcd2vzt conversion utility.
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Analysis
by VulDB Data Team • 01/08/2024
The vulnerability identified as CVE-2023-37576 represents a critical security flaw within GTKWave version 3.3.115, specifically affecting the VCD get_vartoken realloc functionality. This issue manifests as multiple use-after-free conditions that can be exploited through maliciously crafted .vcd files, which are waveform data files commonly used in electronic design automation for visualizing signal behavior. The vulnerability is particularly concerning because it enables arbitrary code execution when a victim opens a specially designed file, making it a significant threat to users who handle waveform data files in their design workflows.
The technical root cause of this vulnerability lies in improper memory management within the vcd2vzt conversion utility, which processes VCD files into a different format. When the get_vartoken function handles memory reallocation during the parsing of malformed VCD data, it fails to properly validate memory references after freeing previously allocated memory blocks. This creates a scenario where subsequent memory operations may access freed memory locations, leading to use-after-free conditions. According to CWE classification, this vulnerability maps to CWE-416 Use After Free, which is a well-documented weakness where software continues to use a pointer after it has been freed, potentially allowing attackers to manipulate memory contents or execute arbitrary code.
The operational impact of this vulnerability extends beyond simple code execution, as it can be leveraged to compromise entire design environments where GTKWave is used for verification and debugging purposes. Attackers could craft malicious VCD files that, when opened by unsuspecting users, would trigger the use-after-free conditions and potentially allow for privilege escalation or system compromise. The attack vector is particularly insidious because it requires only user interaction through file opening, making it difficult to defend against in environments where users frequently exchange waveform data files. This vulnerability aligns with ATT&CK technique T1203 Exploitation for Client Execution, as it exploits a client-side application vulnerability to execute arbitrary code through legitimate application usage patterns.
The remediation strategy for CVE-2023-37576 involves immediate patching of GTKWave to version 3.3.116 or later, which contains the necessary memory management fixes for the vcd2vzt conversion utility. Organizations should implement strict file validation procedures for VCD files received from external sources, particularly in environments where waveform data is frequently shared between teams or with third parties. Security measures should include sandboxing of waveform file processing, automated scanning for potentially malicious VCD files, and user education regarding the risks of opening untrusted waveform data. Additionally, system administrators should monitor for any unusual process behavior or memory access patterns that might indicate exploitation attempts. The vulnerability highlights the importance of robust memory management practices in applications handling untrusted input data, particularly in tools used for critical design verification processes where security breaches could compromise entire hardware development projects.