CVE-2020-37216 Hirschmann HiOS EtherNet/IP Stack Denial of Service

High 8.7 Published Updated

Remote attackers can crash Hirschmann HiOS devices by sending crafted EtherNet/IP packets with invalid length fields, causing denial of service.

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-2020-37216?

CVE-2020-37216 is a high-severity denial of service vulnerability in Belden Hirschmann HiOS, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Hirschmann HiOS devices versions prior to 08.1.00 and 07.1.01 contain a denial of service vulnerability in the EtherNet/IP stack where improper handling of packet length fields allows remote attackers to crash or hang the device. Attackers can send specially crafted UDP EtherNet/IP packets with a length value larger than the actual packet size to render the device inoperable.

Weakness: CWE-20

Which versions are affected by CVE-2020-37216?

How do I fix CVE-2020-37216?

No fix has been published for CVE-2020-37216 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2020-37216 being exploited?

There is no known exploitation of CVE-2020-37216 in the wild and no public exploit code.

Sources

Also known as GHSA-m685-jgfp-vmx9.

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