CVE-2021-32986 Automation Direct CLICK PLC CPU Modules Authentication Bypass Using an Alternate Path or Channel

Critical 9.8 Published 4 Apr 2022 Updated 16 Apr 2025

Attackers can modify PLC logic without authorization if the device remains unlocked after an interrupted session, requiring a power cycle to relock.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-32986?

CVE-2021-32986 is a critical authentication bypass vulnerability in Automation Direct CLICK PLC CPU Modules: C0-1x CPUs, published on 4 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

After Automation Direct CLICK PLC CPU Modules: C0-1x CPUs with firmware prior to v3.00 is unlocked by an authorized user, the unlocked state does not timeout. If the programming software is interrupted, the PLC remains unlocked. All subsequent programming connections are allowed without authorization. The PLC is only relocked by a power cycle, or when the programming software disconnects correctly.

Weakness: CWE-863, CWE-288

Which versions are affected by CVE-2021-32986?

It affects 20 products.

Products include Automationdirect C0-10are-D Firmware, Automationdirect C0-10dd1e-D Firmware, Automationdirect C0-10dd2e-D Firmware, Automationdirect C0-10dre-D Firmware, Automationdirect C0-11are-D Firmware, Automationdirect C0-11dd1e-D Firmware and 14 more.

How do I fix CVE-2021-32986?

No fix has been published for CVE-2021-32986 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2021-32986 being exploited?

There is no known exploitation of CVE-2021-32986 in the wild and no public exploit code.

Sources

Also known as GHSA-j37w-8jcg-6mcp.