CVE-2023-37576

Code execution via stale post-realloc pointer

Published Jan 8, 2024 · Updated Nov 4, 2025

Use-after-free in GTKWave 3.3.115 allows attackers to execute arbitrary code when a crafted VCD file is opened with vcd2vzt. In vcd2vzt.c's VCD token parser, realloc can move the yytext buffer while varsplit still points into the freed allocation, and the stale pointer is later used. The attack requires a user to open attacker-controlled input; successful execution gains the utility process's privileges.

CVSS severity7.8
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in GTKWave 3.3.115 allows attackers to execute arbitrary code when a crafted VCD file is opened with vcd2vzt. In vcd2vzt.c's VCD token parser, realloc can move the yytext buffer while varsplit still points into the freed allocation, and the stale pointer is later used. The attack requires a user to open attacker-controlled input; successful execution gains the utility process's privileges.

The record

CVE
CVE-2023-37576
Published
Jan 8, 2024
Updated
Nov 4, 2025
Vendor
GTKWave
Product
GTKWave
Classifications
CWE-416, T1203, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 8, 2024CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=3.3.115

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

GTKWave · GTKWaveversion=3.3.115

Published CVSS scores

7.8Cisco TalosCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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