CVE-2023-35969 in GTKWave
Summary
by MITRE • 01/08/2024
Multiple heap-based buffer overflow vulnerabilities exist in the fstReaderIterBlocks2 chain_table parsing functionality of GTKWave 3.3.115. A specially crafted .fst file can lead to arbitrary code execution. A victim would need to open a malicious file to trigger these vulnerabilities.This vulnerability concerns the chain_table of `FST_BL_VCDATA` and `FST_BL_VCDATA_DYN_ALIAS` section types.
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Analysis
by VulDB Data Team • 01/08/2024
The CVE-2023-35969 vulnerability represents a critical heap-based buffer overflow affecting GTKWave 3.3.115, a popular waveform viewer for digital design verification. This vulnerability specifically targets the fstReaderIterBlocks2 function within the GTKWave application, which processes FST (Fast Signal Trace) files used in electronic design automation. The flaw occurs during the parsing of chain_table data structures within FST_BL_VCDATA and FST_BL_VCDATA_DYN_ALIAS section types, making it particularly dangerous as these are common data structures in waveform trace files. The vulnerability exists in the memory management handling of these specific section types, where insufficient bounds checking allows attackers to craft malicious FST files that can trigger memory corruption when processed by the application.
The technical implementation of this vulnerability stems from improper input validation within the chain_table parsing logic, which falls under CWE-121 Heap-based Buffer Overflow. When GTKWave processes a malicious FST file containing specially crafted chain_table data, the application fails to properly validate the size and boundaries of the data structures before attempting to copy or process them into heap-allocated memory regions. This allows an attacker to overflow the allocated buffer and potentially overwrite adjacent memory locations, including return addresses and function pointers. The vulnerability is particularly concerning because it operates in the context of file parsing, meaning that merely opening a malicious file with GTKWave can trigger the exploit without requiring any additional user interaction beyond the initial file opening action, making it a prime candidate for social engineering attacks.
The operational impact of CVE-2023-35969 extends beyond simple denial of service, as the heap-based buffer overflow creates opportunities for arbitrary code execution. An attacker who successfully exploits this vulnerability could gain complete control over the victim's system, potentially leading to data theft, system compromise, or further network infiltration. The attack vector is particularly dangerous in electronic design automation environments where engineers frequently open waveform files from various sources, including third-party vendors or collaborative partners. This vulnerability maps to attack techniques described in the MITRE ATT&CK framework under T1203 Exploitation for Client Execution and T1059 Command and Scripting Interpreter, as the exploitation would likely involve crafting malicious FST files that execute code when opened by the vulnerable application. The vulnerability affects any system running GTKWave 3.3.115 or earlier versions, making it widespread in the EDA (Electronic Design Automation) community where waveform viewers are extensively used for debugging digital circuits and verifying design implementations.
Mitigation strategies for CVE-2023-35969 should prioritize immediate patching of affected GTKWave installations to version 3.3.116 or later, which contains the necessary fixes for the buffer overflow conditions. Organizations should implement strict file validation policies for waveform files, particularly those received from external sources, and consider deploying automated scanning tools that can detect malicious FST files before they are opened. Network segmentation and user access controls should be enforced to limit exposure, while regular security awareness training should emphasize the dangers of opening untrusted waveform files. Additionally, system administrators should monitor for suspicious file access patterns and implement application whitelisting policies to prevent execution of unauthorized versions of GTKWave. The vulnerability highlights the importance of input validation in file parsing applications and serves as a reminder of the critical security considerations needed in EDA tools that handle potentially malicious user-supplied data. Organizations should also consider implementing sandboxing techniques for waveform file processing and maintaining up-to-date vulnerability management procedures to quickly respond to similar threats in the future.