CVE-2021-23138

Code execution via unchecked project-file attribute lengths

Published Jan 14, 2022 · Updated Apr 16, 2025

Stack-based buffer overflows in WECON LeviStudioU 2019-09-21 and earlier allow remote attackers to execute code via malicious project files. Multiple UMP and XML parsers copy unchecked attribute values, including BgOnOffBitAddr and ContralAddr, into fixed-length stack buffers. Execution requires the target to open the file or visit a malicious page, and code runs with the application's privileges.

CVSS severity7.8
High
EPSS probability8.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflows in WECON LeviStudioU 2019-09-21 and earlier allow remote attackers to execute code via malicious project files. Multiple UMP and XML parsers copy unchecked attribute values, including BgOnOffBitAddr and ContralAddr, into fixed-length stack buffers. Execution requires the target to open the file or visit a malicious page, and code runs with the application's privileges.

The record

CVE
CVE-2021-23138
Published
Jan 14, 2022
Updated
Apr 16, 2025
Vendor
WECON Technology Co., Ltd.
Product
LEVIStudioU
Classifications
CWE-121, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 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=All <=2019-09-21

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

WECON Technology Co., Ltd. · LEVIStudioUversion=All <=2019-09-21

Published CVSS scores

7.8ICS-CERTCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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