CVE-2023-37577 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 vcd2lxt2 conversion utility.
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Analysis
by VulDB Data Team • 01/08/2024
The vulnerability identified as CVE-2023-37577 represents a critical security flaw within GTKWave version 3.3.115 that manifests through multiple use-after-free conditions in the VCD get_vartoken realloc functionality. This issue specifically affects the vcd2lxt2 conversion utility, which serves as a bridge for converting Value Change Dump files to LXT format. The vulnerability stems from improper memory management practices where freed memory locations are accessed after being reallocated, creating exploitable conditions that can be leveraged by malicious actors.
The technical exploitation of this vulnerability occurs through the manipulation of specially crafted .vcd files that trigger the use-after-free conditions during the vcd2lxt2 conversion process. When a victim opens such a malicious file, the application's handling of variable tokens within the VCD parsing routine leads to memory corruption that can be exploited to execute arbitrary code. The flaw exists in the memory allocation and deallocation sequence where the get_vartoken function fails to properly validate memory references after reallocation operations, allowing attackers to corrupt memory layout and potentially redirect execution flow.
This vulnerability has significant operational impact within environments that utilize GTKWave for waveform analysis and simulation verification. The use-after-free conditions create a high-risk scenario where remote code execution becomes possible through simple file opening actions, eliminating the need for complex exploitation techniques or user interaction beyond the initial file access. The attack vector is particularly concerning because it can be delivered through standard file sharing mechanisms or automated systems, making it accessible to threat actors with minimal technical expertise.
Security professionals should note that this vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software applications. The ATT&CK framework categorizes this as a privilege escalation technique through application input manipulation, where the initial compromise occurs through file processing rather than network-based attacks. Organizations using GTKWave for simulation verification, circuit analysis, or digital design validation face elevated risk when processing untrusted VCD files, particularly in collaborative environments where file sharing occurs without proper sanitization.
Mitigation strategies should prioritize immediate patching of GTKWave installations to versions that address the memory management flaws in the VCD parsing routines. System administrators should implement strict file validation policies for VCD files, particularly those received from external sources or untrusted environments. The implementation of sandboxing techniques around the vcd2lxt2 utility can provide additional defense layers, while network segmentation and access controls should limit potential exploitation vectors. Regular security assessments of waveform analysis tools and automated vulnerability scanning should be implemented to identify similar memory corruption vulnerabilities in other simulation and verification environments.
The broader implications extend to software development practices, highlighting the importance of rigorous memory management testing and code review processes for applications handling user-supplied data. This vulnerability demonstrates how seemingly benign file processing operations can become attack surfaces when proper memory safety checks are omitted. Security teams should consider implementing automated testing frameworks that specifically target use-after-free conditions and other memory corruption vulnerabilities during software development lifecycle phases to prevent similar issues from emerging in future releases.
Organizations should also establish secure file handling protocols that include automated scanning of VCD files for malformed structures and implement strict input validation for all waveform file formats processed through simulation tools. The vulnerability serves as a reminder of the critical importance of memory safety in applications that process complex data formats, particularly in domains where simulation accuracy and security are paramount requirements for system reliability and integrity.