CVE-2020-6994: Belden Hirschmann Hios

Critical severity, CVSS 9.8. EPSS: 1.6% chance of exploitation in the next 30 days.

A buffer overflow vulnerability was found in some devices of Hirschmann Automation and Control HiOS and HiSecOS. The vulnerability is due to improper parsing of URL arguments. An attacker could exploit this vulnerability by specially crafting HTTP requests to overflow an internal buffer. The following devices using HiOS Version 07.0.02 and lower are affected: RSP, RSPE, RSPS, RSPL, MSP, EES, EES, EESX, GRS, OS, RED. The following devices using HiSecOS Version 03.2.00 and lower are affected: EAGLE20/30.

Affected products

• Belden Hirschmann Hios: up to and including 07.0.02
• Belden Hirschmann Hisecos: up to and including 03.2.00

Published 2020-04-03. Last modified 2026-06-17.