CVE-2023-39413

What it actually does

Integer underflow during left shift in LXT2 radix iteration allows memory corruption when parsing a crafted .lxt2 file.

Why it matters to the business

Attackers can achieve code execution on analyst workstations that process waveform files, potentially leading to theft of proprietary design data or further lateral movement with low likelihood given current exploitation metrics.

How an attack unfolds

An attacker crafts a malicious .lxt2 file that triggers an integer underflow in the shift operation inside lxt2_rd_iter_radix; the victim opens the file in GTKWave, causing memory corruption that an available public exploit can leverage for arbitrary code execution.

How to fix it

Upgrade GTKWave to a version that corrects the LXT2 parser integer handling; until a fixed release is available, avoid opening untrusted .lxt2 files and consider sandboxing or alternative viewers.

How to confirm the fix worked

Confirm the installed GTKWave build contains the corrected LXT2 iteration logic by reviewing release notes or source for the shift-operation bounds check; test with known-malformed sample files in an isolated environment.

Typical attack path

1. Craft .lxt2 file containing values that cause underflow in radix shift calculation
2. Deliver the file via email, download link, or shared storage
3. Victim opens the file in the vulnerable GTKWave application
4. Underflow leads to memory corruption and potential control-flow hijack

How to detect it

Monitor process creation logs for GTKWave launched against files from untrusted sources; inspect crash dumps or memory error logs for LXT2 radix iteration faults; search endpoint telemetry for unexpected child processes or network activity immediately after .lxt2 file access.

What your security team should do

• Block or quarantine .lxt2 attachments at mail and file gateways until fixed builds are deployed
• Update GTKWave as soon as a corrected package is released
• Add .lxt2 file-type restrictions or viewer sandbox policies for hardware and EDA teams