Memory corruption via undersized times allocation
Published Jan 8, 2024 · Updated Nov 4, 2025
Integer overflow in GTKWave 3.3.115 allows context-dependent attackers to corrupt memory through a crafted VZT file. In 32-bit mode, vzt_rd_block_vch_decode multiplies an untrusted nonzero num_time_ticks value by eight without detecting wraparound, allocates an undersized times array, and fills it with that many 64-bit values. A victim must open the file; the out-of-bounds writes corrupt heap memory, while threading and heap layout determine whether the result is a crash or arbitrary code execution.
Summary
What happened
Integer overflow in GTKWave 3.3.115 allows context-dependent attackers to corrupt memory through a crafted VZT file. In 32-bit mode, vzt_rd_block_vch_decode multiplies an untrusted nonzero num_time_ticks value by eight without detecting wraparound, allocates an undersized times array, and fills it with that many 64-bit values. A victim must open the file; the out-of-bounds writes corrupt heap memory, while threading and heap layout determine whether the result is a crash or arbitrary code execution.
The record
- CVE
- CVE-2023-38650
- 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
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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
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Weakness, pattern, technique
Public exploit references
- Cisco Talos num_time_ticks proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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