CVE-2022-37301Network attack vector

Controller crash via Modbus TCP integer underflow

Published Nov 22, 2022 · Updated Apr 28, 2025

Integer underflow in Modbus TCP handling in Schneider Electric Modicon PAC controllers allows remote attackers to crash the controller. The Modbus TCP input-processing path performs arithmetic that wraps below zero, leading to invalid memory access. No authentication or user interaction is required; network access to Modbus TCP permits an availability-only service interruption.

CVSS severity7.5
High
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Modbus TCP handling in Schneider Electric Modicon PAC controllers allows remote attackers to crash the controller. The Modbus TCP input-processing path performs arithmetic that wraps below zero, leading to invalid memory access. No authentication or user interaction is required; network access to Modbus TCP permits an availability-only service interruption.

The record

CVE
CVE-2022-37301
Published
Nov 22, 2022
Updated
Apr 28, 2025
Vendor
Distributed Data Systems
Product
Modicon M580 CPU
Classifications
CWE-191, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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=V <=3.22

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Distributed Data Systems · Modicon M580 CPUversion=V <=3.22
Distributed Data Systems · Modicon Momentum Unity M1E Processorversion=All Versions
Distributed Data Systems · Modicon MC80version=V <=1.7
Distributed Data Systems · Modicon M340 CPUversion=V <=3.40

Published CVSS scores

7.5Schneider Electric SECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T0814Denial of Service

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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