Review reviewHigh

CVE-2020-37216

Belden Hirschmann HiOS

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.

CVSS: 8.7
EPSS: 0.92%
CISA KEV: Not listed
Published: 2026.04.04

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.92%

Technical severityCVSS 8.7

Vulnerability overview

Affected product and versions

Product: Belden Hirschmann HiOS
Affected versions: >= 05.00.00 <= 08.0.00
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Belden Hirschmann HiOS and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE: CWE-20