CVE-2021-22681Known exploitationNetwork attack vector

Controller code modification via extractable signing key

Published Mar 3, 2021 · Updated Mar 6, 2026

Authentication bypass in Rockwell Automation Logix software and controllers allows remote attackers to alter controller code. An extractable internal licensing key signs engineering-station traffic, letting third-party tools impersonate trusted software to a controller. Network access to a controller is required; unauthenticated use can change its configuration or application code and disrupt the controlled process.

CVSS severity10.0
Critical
EPSS probability63.63%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Rockwell Automation Logix software and controllers allows remote attackers to alter controller code. An extractable internal licensing key signs engineering-station traffic, letting third-party tools impersonate trusted software to a controller. Network access to a controller is required; unauthenticated use can change its configuration or application code and disrupt the controlled process.

The record

CVE
CVE-2021-22681
Published
Mar 3, 2021
Updated
Mar 6, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-522, T0866
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 3, 2021CVE publishedPublication date reported by the CVE source.
  2. Mar 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
10.0Rockwell AutomationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-522Insufficiently Protected Credentials
T0866Exploitation of Remote Services

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.

Reported exploitation

Technologies

Your stack

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Your stack

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