CVE-2023-38649 in GTKWave
Summary
by MITRE • 01/08/2024
Multiple out-of-bounds write vulnerabilities exist in the VZT vzt_rd_get_facname decompression functionality of GTKWave 3.3.115. A specially crafted .vzt file can lead to arbitrary code execution. A victim would need to open a malicious file to trigger these vulnerabilities.This vulnerability concerns the out-of-bounds write perfomed by the string copy loop.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/08/2024
The vulnerability identified as CVE-2023-38649 represents a critical security flaw within GTKWave 3.3.115's VZT file processing capabilities, specifically within the vzt_rd_get_facname decompression function. This issue manifests as multiple out-of-bounds write vulnerabilities that can be exploited through maliciously crafted .vzt files, potentially enabling remote code execution attacks. The vulnerability stems from insufficient bounds checking during string copy operations within the decompression routine, creating a pathway for attackers to manipulate memory layout and execute arbitrary code on affected systems. The flaw specifically targets the decompression functionality of the VZT format, which is used for storing waveform data in digital simulation environments, making it particularly dangerous for users who frequently process simulation results from untrusted sources.
The technical implementation of this vulnerability involves a string copy loop that fails to properly validate buffer boundaries during the decompression process of facility names within VZT files. When GTKWave processes a maliciously constructed .vzt file, the vzt_rd_get_facname function attempts to copy data into memory buffers without adequate bounds verification, leading to out-of-bounds memory writes. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and more specifically aligns with CWE-787, representing out-of-bounds write vulnerabilities. The attack vector requires user interaction through file opening, making it a classic example of a file-based exploit that leverages the trust users place in waveform visualization tools. The memory corruption occurs during the decompression phase when facility names are extracted from compressed data structures, where the copy loop overwrites adjacent memory locations, potentially corrupting program execution flow or heap metadata.
The operational impact of CVE-2023-38649 extends beyond simple code execution, as it represents a significant threat to digital design verification environments where GTKWave is extensively used. System administrators and design engineers who regularly process simulation results from multiple sources face elevated risk, particularly in collaborative environments where file sharing occurs without proper sanitization. The vulnerability affects both local and network-based attack scenarios, as attackers can distribute malicious .vzt files through various channels including email attachments, shared repositories, or automated testing environments. From an ATT&CK framework perspective, this vulnerability maps to T1203, which involves exploitation of known vulnerabilities, and potentially T1059 for command and scripting interface usage once initial compromise occurs. The attack surface includes not only individual users but also automated build systems, continuous integration pipelines, and collaborative design platforms that rely on GTKWave for waveform analysis, making the impact far-reaching across electronic design automation workflows.
Mitigation strategies for CVE-2023-38649 should prioritize immediate software updates from the GTKWave development team, as version 3.3.116 or later should contain patches addressing the out-of-bounds write conditions. Organizations should implement strict file validation policies for waveform data, particularly when processing files from external sources or untrusted parties, and consider deploying sandboxed environments for waveform file analysis. Additional defensive measures include network-based file filtering to block .vzt file extensions when they originate from untrusted domains, implementing automated malware scanning for waveform data, and establishing secure file handling procedures for design verification environments. Security teams should also monitor for indicators of compromise related to this vulnerability, including unusual file access patterns or memory corruption events that might suggest exploitation attempts. The vulnerability underscores the importance of input validation in decompression routines and highlights the need for robust bounds checking in legacy code handling compressed data structures, particularly in tools used for critical design verification processes within the semiconductor and electronics industries.