CVE-2022-4856Public exploit

Code execution via unchecked MBS string copy

Published Dec 30, 2022 · Updated Aug 3, 2024

Stack-based buffer overflow in Modbus Tools Modbus Slave 7.5.0 through 7.5.1 allows attackers to execute code through a crafted .mbs file. The .mbs parser trusts a file-supplied string length, converts the data to Unicode, and uses lstrcpyW to copy it into a 64-byte stack buffer, permitting an SEH overwrite. A user must open the file; successful exploitation runs code in that user's process context and can crash the application.

CVSS severity7.8
High
EPSS probability0.59%
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 overflow in Modbus Tools Modbus Slave 7.5.0 through 7.5.1 allows attackers to execute code through a crafted .mbs file. The .mbs parser trusts a file-supplied string length, converts the data to Unicode, and uses lstrcpyW to copy it into a 64-byte stack buffer, permitting an SEH overwrite. A user must open the file; successful exploitation runs code in that user's process context and can crash the application.

The record

CVE
CVE-2022-4856
Published
Dec 30, 2022
Updated
Aug 3, 2024
Vendor
Modbus Tools
Product
Modbus Slave
Classifications
CWE-120, T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 30, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=7.5.0
  2. Affected versionversion=7.5.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Modbus Tools · Modbus Slaveversion=7.5.0; version=7.5.1

Published CVSS scores

6.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
7.8NIST NVDCVSS: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-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1204.002User Execution Malicious File
T1203Exploitation for Client Execution

Public exploit references

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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