CVE-2023-3596Network attack vector

Remote service interruption via crafted CIP messages

Published Jul 12, 2023 · Updated Nov 7, 2024

Out-of-bounds write in Rockwell Automation 1756-EN4* firmware 5.001 and earlier allows remote attackers to interrupt module service. The communication module mishandles maliciously crafted CIP messages and writes beyond a buffer boundary, triggering a target-system assertion. Network connectivity to the module is required, but authentication and user interaction are not; successful exploitation stops module availability.

CVSS severity7.5
High
EPSS probability3.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Rockwell Automation 1756-EN4* firmware 5.001 and earlier allows remote attackers to interrupt module service. The communication module mishandles maliciously crafted CIP messages and writes beyond a buffer boundary, triggering a target-system assertion. Network connectivity to the module is required, but authentication and user interaction are not; successful exploitation stops module availability.

The record

CVE
CVE-2023-3596
Published
Jul 12, 2023
Updated
Nov 7, 2024
Vendor
Rockwell Automation
Product
1756-EN4TRXT
Classifications
CWE-787, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2024Record 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=0 <=5.001
  2. Affected versionversion=<=5.001

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rockwell Automation · 1756-EN4TRXTversion=0 <=5.001; version=<=5.001
Rockwell Automation · 1756-EN4TRversion=0 <=5.001; version=<=5.001
Rockwell Automation · 1756-EN4TRKversion=0 <=5.001; version=<=5.001

Published CVSS scores

7.5Rockwell AutomationCVSS: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.

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-787Out-of-bounds Write
T0814Denial of Service

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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