CVE-2023-38583

What it actually does

Stack-based buffer overflow in LXT2 lxt2_rd_expand_integer_to_bits function allowing arbitrary code execution upon parsing a malformed .lxt2 file.

Why it matters to the business

Attackers can fully compromise analysis workstations or build environments that open untrusted waveform files, resulting in data theft, persistence, or lateral movement with moderate urgency given the age of the disclosure and available public exploits.

How an attack unfolds

An attacker crafts a malicious .lxt2 file that overflows the stack buffer in the integer expansion routine; the victim opens the file in GTKWave 3.3.115, triggering the overflow and allowing the attacker to execute arbitrary code under the privileges of the GTKWave process.

How to fix it

Upgrade GTKWave to the latest available version that resolves the LXT2 parsing issue; if no fixed release exists yet, avoid opening untrusted .lxt2 files and consider sandboxing or alternative waveform viewers until a patch is released.

How to confirm the fix worked

Confirm GTKWave version is newer than 3.3.115, test with known-good and known-malicious LXT2 samples in a controlled environment, and verify absence of the vulnerable expand_integer_to_bits code path via binary analysis or source inspection.

Typical attack path

1. Craft a specially malformed .lxt2 file that triggers the integer-to-bits expansion overflow
2. Deliver the file to the target via email, download link, or shared storage
3. Victim opens the file using GTKWave
4. Overflow occurs during file parsing, leading to arbitrary code execution

How to detect it

Review system logs and process execution history for GTKWave launches involving externally sourced .lxt2 files; look for segmentation faults, unexpected child processes, or anomalous memory usage immediately after file open events.

• gtkwave.*\.lxt2
• lxt2_rd_expand_integer_to_bits
• segmentation fault.*gtkwave

What your security team should do

• Immediately restrict opening of .lxt2 files from untrusted sources
• Monitor for new GTKWave releases and apply the fix as soon as published
• Add file-type sandboxing or application allow-listing for waveform analysis tools
• Scan historical .lxt2 artifacts for signs of prior exploitation attempts