CVE-2023-35970 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 the `FST_BL_VCDATA_DYN_ALIAS2` section type.
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Analysis
by VulDB Data Team • 01/08/2024
The CVE-2023-35970 vulnerability represents a critical heap-based buffer overflow within GTKWave 3.3.115's fstReaderIterBlocks2 functionality, specifically targeting the chain_table parsing mechanism of the FST_BL_VCDATA_DYN_ALIAS2 section type. This vulnerability resides in the file format parsing logic that handles FST (Fast Signal Trace) files, which are commonly used for waveform visualization in digital design verification environments. The flaw manifests when the application processes maliciously crafted .fst files that exploit improper bounds checking during chain_table data structure parsing, creating opportunities for remote code execution through user interaction with malicious files.
The technical implementation of this vulnerability stems from inadequate input validation within the chain_table parsing routine that processes FST_BL_VCDATA_DYN_ALIAS2 section types. When GTKWave encounters a malformed chain_table structure within the FST file, the application fails to properly validate the size parameters and memory allocation boundaries before copying data into heap-allocated buffers. This deficiency allows attackers to craft FST files with oversized or malformed chain_table entries that exceed the allocated buffer boundaries, resulting in heap corruption that can be exploited to overwrite adjacent memory regions. The vulnerability is particularly dangerous because it operates within the file parsing chain that executes during normal file opening operations, requiring no special privileges beyond standard user execution.
The operational impact of CVE-2023-35970 extends beyond simple arbitrary code execution, as it represents a privilege escalation vector within digital design verification environments where GTKWave is commonly deployed. Attackers can leverage this vulnerability to execute malicious code with the privileges of the user running GTKWave, potentially leading to complete system compromise if the application is run with elevated permissions. The vulnerability affects the broader ecosystem of digital verification tools and design environments where FST files are processed, including simulation environments, automated testing frameworks, and verification platforms. This creates a significant risk for hardware design verification teams who may unknowingly open malicious FST files during normal workflow operations, as the attack surface includes not just direct exploitation but also potential supply chain compromise through malicious design files.
Mitigation strategies for CVE-2023-35970 should prioritize immediate patching of GTKWave installations to versions that address the heap overflow conditions in chain_table parsing. Organizations should implement strict file validation policies that prevent automatic opening of untrusted FST files, particularly in collaborative environments where design files may originate from multiple sources. Network-based controls such as file type filtering and sandboxed execution environments can provide additional protection layers. Security practitioners should monitor for indicators of compromise related to FST file access patterns and implement automated scanning of design verification environments for potentially malicious file content. The vulnerability aligns with CWE-121 heap-based buffer overflow classifications and represents a potential ATT&CK technique involving execution through file parsing and exploitation of application vulnerabilities, emphasizing the need for layered defensive measures including input validation, memory protection mechanisms, and regular security assessments of design verification toolchains.