CVE-2023-38618

What it actually does

Integer overflow during allocation of the rows array in VZT facgeometry parsing allows out-of-bounds memory access and subsequent arbitrary code execution within the GTKWave process.

Why it matters to the business

Attackers can achieve full control over systems where users open malicious waveform files, leading to data theft, ransomware deployment, or lateral movement with high urgency due to public exploit availability and over 1000 days of exposure.

How an attack unfolds

An attacker crafts a malicious .vzt file that triggers an integer overflow when the rows array is allocated during facgeometry parsing. The victim opens the file in an affected GTKWave version, causing memory corruption that is turned into arbitrary code execution. No named threat actors are associated with this issue.

How to fix it

Upgrade GTKWave to the latest patched release that resolves the VZT parsing integer overflow. Until a fix is available, disable opening of untrusted .vzt files and restrict use of the tool on sensitive systems.

How to confirm the fix worked

Confirm the installed GTKWave version is newer than 3.3.115 and test that crafted .vzt files no longer trigger crashes or unexpected memory allocations during facgeometry parsing.

Typical attack path

1. Craft malicious .vzt file exploiting integer overflow in facgeometry rows allocation
2. Deliver file via email, download link, or shared storage
3. Victim opens file in vulnerable GTKWave instance
4. Overflow corrupts memory structures enabling code execution
5. Attacker payload executes with privileges of the GTKWave process

How to detect it

Review file-open logs and process execution history for GTKWave launched against .vzt files from untrusted sources; inspect crash dumps or memory logs showing abnormal allocation sizes during VZT parsing.

What your security team should do

• Prioritize patching GTKWave across all developer and engineering workstations immediately due to public exploit availability
• Implement application allow-listing or sandboxing for waveform viewers handling untrusted files
• Add .vzt file type to email and download security scanning rules
• Monitor for new fixed versions and schedule deployment within 30 days