Arbitrary code execution via undersized VZT buffers
Published Jan 8, 2024 · Updated Nov 4, 2025
Integer overflow in GTKWave 3.3.115 allows context-dependent attackers to execute arbitrary code through a crafted VZT file. In vzt_rd_init_smp, attacker-controlled msb and lsb fields can make longest_len wrap to 0xffffffff, so adding one allocates a tiny buffer that vzt_rd_fac_value then overwrites. Exploitation requires a victim to open the file in the GUI or process it with an affected VZT utility, after which controlled heap writes can execute code in that process.
Summary
What happened
Integer overflow in GTKWave 3.3.115 allows context-dependent attackers to execute arbitrary code through a crafted VZT file. In vzt_rd_init_smp, attacker-controlled msb and lsb fields can make longest_len wrap to 0xffffffff, so adding one allocates a tiny buffer that vzt_rd_fac_value then overwrites. Exploitation requires a victim to open the file in the GUI or process it with an affected VZT utility, after which controlled heap writes can execute code in that process.
The record
- CVE
- CVE-2023-35004
- Published
- Jan 8, 2024
- Updated
- Nov 4, 2025
- Vendor
- GTKWave
- Product
- GTKWave
- Classifications
- CWE-190, 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 VZT longest_len proof of conceptproof 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