CVE-2023-35703Public exploit

Arbitrary code execution via unbounded LEB128 decoding

Published Jan 8, 2024 · Updated Nov 4, 2025

Stack-based buffer overflow in GTKWave 3.3.115 allows context-dependent attackers to execute arbitrary code when a victim opens a crafted FST file. fstReaderVarint64 copies attacker-controlled LEB128 bytes into a 16-byte stack buffer until a byte clears its high bit, without bounding the write. Execution requires a victim to open the file, including through a registered waveform-file association, and runs with that victim's privileges.

CVSS severity7.8
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stack-based buffer overflow in GTKWave 3.3.115 allows context-dependent attackers to execute arbitrary code when a victim opens a crafted FST file. fstReaderVarint64 copies attacker-controlled LEB128 bytes into a 16-byte stack buffer until a byte clears its high bit, without bounding the write. Execution requires a victim to open the file, including through a registered waveform-file association, and runs with that victim's privileges.

The record

CVE
CVE-2023-35703
Published
Jan 8, 2024
Updated
Nov 4, 2025
Vendor
GTKWave
Product
GTKWave
Classifications
CWE-121, CWE-787, 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

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.

  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

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution
T1204.002User Execution Malicious File

Public exploit references

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