CVE-2023-37442

What it actually does

Out-of-bounds read in VCD variable definition parsing within GTKWave allows memory corruption that can be leveraged for arbitrary code execution when a crafted file is processed.

Why it matters to the business

Compromise of analyst workstations or servers running waveform viewing tools can lead to unauthorized code execution, potential data theft, and disruption of hardware verification workflows.

How an attack unfolds

An attacker creates a malformed VCD file containing out-of-bounds variable definitions, then delivers it to a victim who opens the file using the GTKWave GUI; the default VCD parser triggers the read flaw resulting in code execution.

How to fix it

Upgrade GTKWave to the latest available version that resolves the VCD parsing issues; until a patch is released, avoid opening untrusted or externally sourced .vcd files and consider sandboxing the application.

How to confirm the fix worked

Confirm GTKWave version is current, attempt to open known-good and known-malicious test VCD files in an isolated environment, and monitor for application crashes or unexpected behavior during parsing.

Typical attack path

1. Craft malicious .vcd file exploiting VCD var section parsing
2. Distribute file via email, download link, or shared storage
3. Victim opens file through GTKWave GUI
4. Parser processes malformed variable definitions triggering out-of-bounds read
5. Memory corruption leads to arbitrary code execution

How to detect it

Review system and application logs for GTKWave processes opening .vcd files from unusual locations, unexpected crashes or segfaults during VCD parsing, and any child processes spawned by gtkwave that are not typical for waveform viewing.

• gtkwave.*\.vcd
• segmentation fault.*gtkwave
• VCD parse error

What your security team should do

• Immediately restrict opening of .vcd files from untrusted sources
• Deploy application allow-listing or sandboxing for GTKWave
• Monitor vendor announcements for patch availability and deploy promptly
• Educate hardware and verification teams on risks of opening external waveform files