Automation Direct CLICK PLC CPU Modules Authentication Bypass Using an Alternate Path or Channel

published 2022-04-04 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-19705

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits: 0; none known

All programming connections receive the same unlocked privileges, which can result in a privilege escalation. During the time Automation Direct CLICK PLC CPU Modules: C0-1x CPUs with firmware prior to v3.00 is unlocked by an authorized user, an attacker can connect to the PLC and read the project without authorization.

Patch / fix

fixed in 1

Automation Direct CLICK PLC CPU Modules: C0-1x CPUs 3.00

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-166-02 updated 2021-06-15 cvss 9.8

Automation Direct CLICK PLC CPU Modules

Automation Direct CLICK PLC CPU Modules <v3.00
affected: mitigation “Automation Direct reports these vulnerabilities are all mitigated by Version 3.00 and recommends users update software and firmware to the latest version.” automationdirect.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 18 mo ago (2025-04-16)

Exploit prediction

1.11% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

Automation Direct CLICK PLC CPU Modules: C0-1x CPUs

Classification

Weakness

CWE-288 Authentication Bypass Using an Alternate Path or Channel
CWE-287 Improper Authentication

References

cisa.gov /uscert/ics/advisories/icsa-21-166-02
third-party-advisory, us-government-resource

Sources

CVE List CVE-2021-32984
NVD CVE-2021-32984

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary