CVE-2024-36981Public exploitNetwork attack vector

Runtime crash via unsigned error-length comparison

Published Sep 18, 2024 · Updated Nov 4, 2025

An out-of-bounds read in OpenPLC Runtime v3 b4702061dc14d1024856f71b4543298d77007b88 allows remote attackers to crash the runtime. In sendUnitData, an unsupported PCCC command returns -1 through a uint16_t; comparison with signed -1 fails, so memmove receives 0x10006 as its count and reads beyond the request buffer. No authentication or user interaction is required; crafted EtherNet/IP SendUnitData requests can terminate the OpenPLC process with SIGSEGV.

CVSS severity7.5
High
EPSS probability1.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds read in OpenPLC Runtime v3 b4702061dc14d1024856f71b4543298d77007b88 allows remote attackers to crash the runtime. In sendUnitData, an unsupported PCCC command returns -1 through a uint16_t; comparison with signed -1 fails, so memmove receives 0x10006 as its count and reads beyond the request buffer. No authentication or user interaction is required; crafted EtherNet/IP SendUnitData requests can terminate the OpenPLC process with SIGSEGV.

The record

CVE
CVE-2024-36981
Published
Sep 18, 2024
Updated
Nov 4, 2025
Vendor
OpenPLC Project
Product
OpenPLC Runtime v3
Classifications
CWE-125, CAPEC-540, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 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

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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=b4702061dc14d1024856f71b4543298d77007b88

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenPLC Project · OpenPLC Runtime v3version=b4702061dc14d1024856f71b4543298d77007b88

Published CVSS scores

7.5Cisco TalosCVSS: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 exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CAPEC-540Overread Buffers
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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