CVE-2021-32986Network attack vector

Unauthenticated programming access via persistent unlocked state

Published Apr 4, 2022 · Updated Apr 16, 2025

Authentication bypass in AutomationDirect CLICK PLC firmware before 3.00 allows remote attackers to make unauthorized programming connections. The controller fails to expire its unlocked state when the programming software is interrupted, so later programming sessions inherit authorization. Exploitation requires an authorized user to unlock the PLC before the client terminates abnormally; later unauthenticated sessions retain programming access.

CVSS severity9.8
Critical
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in AutomationDirect CLICK PLC firmware before 3.00 allows remote attackers to make unauthorized programming connections. The controller fails to expire its unlocked state when the programming software is interrupted, so later programming sessions inherit authorization. Exploitation requires an authorized user to unlock the PLC before the client terminates abnormally; later unauthenticated sessions retain programming access.

The record

CVE
CVE-2021-32986
Published
Apr 4, 2022
Updated
Apr 16, 2025
Vendor
AutomationDirect
Product
CLICK PLC
Classifications
CWE-863, CWE-288, T0866
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 4, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 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=unspecified <3.00

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

AutomationDirect · CLICK PLCversion=unspecified <3.00

Published CVSS scores

9.8ICS-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
CWE-288Authentication Bypass Using an Alternate Path or Channel
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.

Technologies

Your stack

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Your stack

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