CVE-2023-1424Network attack vector

Unauthenticated code execution via oversized MELSOFT filepath

Published May 24, 2023 · Updated Mar 5, 2025

Stack-based buffer overflow in Mitsubishi Electric MELSEC iQ-F and iQ-R CPU modules allows remote attackers to execute code or crash the PLC. In analyzed FX5U firmware, MELSOFT Direct handlers pass an attacker-controlled filepath length to memcpy, which copies into a 0x84-byte stack buffer. Sending a crafted UDP packet to port 5560 requires no authentication; a resulting service interruption requires a system reset.

CVSS severity10.0
Critical
EPSS probability3.44%
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 Mitsubishi Electric MELSEC iQ-F and iQ-R CPU modules allows remote attackers to execute code or crash the PLC. In analyzed FX5U firmware, MELSOFT Direct handlers pass an attacker-controlled filepath length to memcpy, which copies into a 0x84-byte stack buffer. Sending a crafted UDP packet to port 5560 requires no authentication; a resulting service interruption requires a system reset.

The record

CVE
CVE-2023-1424
Published
May 24, 2023
Updated
Mar 5, 2025
Vendor
Mitsubishi Electric Corporation
Product
MELSEC iQ-R Series R16ENCPU
Classifications
CWE-120, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 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=versions from 12 to 68

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mitsubishi Electric Corporation · MELSEC iQ-R Series R16ENCPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-R Series R32CPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-64MR/ESversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R16CPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-32MT/DSSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series Safety CPU R120SFCPUversion=versions from 26 to 31
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-80MR/ESversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R16PCPUversion=versions from 3 to 37
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-64MT/DSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-32MT/ESSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-32MT/Dversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-64MT/DSSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R120PCPUversion=versions from 3 to 37
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-80MT/ESSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-32MR/DSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series Safety CPU R16SFCPUversion=versions from 26 to 31
Mitsubishi Electric Corporation · MELSEC iQ-R Series R32PCPUversion=versions from 3 to 37
Mitsubishi Electric Corporation · MELSEC iQ-R Series R00CPUversion=versions 35 and prior
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-80MT/DSSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-80MT/ESversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-32MT/DSSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-32MR/ESversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-64MT/ESSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-32MT/ESversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-64MR/DSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R04ENCPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-R Series R08ENCPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-64MT/Dversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-32MR/DS-TSversion=versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R32ENCPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-R Series R08CPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-32MT/DSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-80MT/DSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-64MT/DSSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R04CPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-32MT/DS-TSversion=versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-80MR/DSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R08PCPUversion=versions from 3 to 37
Mitsubishi Electric Corporation · MELSEC iQ-R Series Safety CPU R08SFCPUversion=versions from 26 to 31
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-96MT/Dversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5U-64MT/ESversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R01CPUversion=versions 35 and prior
Mitsubishi Electric Corporation · MELSEC iQ-R Series R120ENCPUversion=versions from 12 to 68
Mitsubishi Electric Corporation · MELSEC iQ-R Series Safety CPU R32SFCPUversion=versions from 26 to 31
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-96MT/DSSversion=Serial number 17X**** or later, versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R02CPUversion=versions 35 and prior
Mitsubishi Electric Corporation · MELSEC iQ-F Series FX5UC-32MT/DSS-TSversion=versions from 1.220 to 1.281
Mitsubishi Electric Corporation · MELSEC iQ-R Series R120CPUversion=versions from 12 to 68

Published CVSS scores

8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
10.0Mitsubishi Electric CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

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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