Code execution via post-header VCD variable definition
Published Jan 8, 2024 · Updated Nov 4, 2025
Out-of-bounds write in GTKWave 3.3.115 allows local users to execute arbitrary code by supplying a crafted VCD file to vcd2vzt. The vcd2vzt VCD parser accepts a $var definition after $enddefinitions, changes hash-range bounds after allocating the symbol index, and later uses those changed bounds for an out-of-bounds lookup that enables attacker-controlled writes. Execution requires a user to process the malicious file with vcd2vzt, after which the code runs with that user's privileges.
Summary
What happened
Out-of-bounds write in GTKWave 3.3.115 allows local users to execute arbitrary code by supplying a crafted VCD file to vcd2vzt. The vcd2vzt VCD parser accepts a $var definition after $enddefinitions, changes hash-range bounds after allocating the symbol index, and later uses those changed bounds for an out-of-bounds lookup that enables attacker-controlled writes. Execution requires a user to process the malicious file with vcd2vzt, after which the code runs with that user's privileges.
The record
- CVE
- CVE-2023-37445
- Published
- Jan 8, 2024
- Updated
- Nov 4, 2025
- Vendor
- GTKWave
- Product
- GTKWave
- Classifications
- CWE-119, T1204.002, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 8, 2024CVE publishedPublication date reported by the CVE source.
- Nov 4, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.3.115
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Cisco Talos crafted VCD trigger exampleproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo