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Fencer Intel
critical 9.8

CVE-2020-6994 json

A buffer overflow vulnerability was found in some devices of Hirschmann Automation and Control HiOS and HiSecOS.

published 6y ago modified 4mo ago also EUVD-2020-28134

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

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.

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Vendor advisories

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

cisa ICSA-22-270-01 updated cvss 9.8

Hitachi Energy AFS660/AFS665

  • Hitachi Energy AFS660/AFS665 <= 7.0.02
    affected: mitigation “Hitachi Energy recommends users update to 7.1.05 or later or apply mitigation strategies.” search.abb.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 ICSA-22-263-02 updated cvss 9.8

Hitachi Energy AFF660/665 Series

  • Hitachi Energy AFF660 FW <= 03.0.02 Hitachi Energy AFF665 FW <= 03.0.02
    affected: mitigation “Hitachi Energy for AFF660 FW and AFF665 FW versions 03.0.02 and prior recommends users to implement the following security measures:” search.abb.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 ICSA-20-091-01 updated cvss 9.8

Hirschmann Automation and Control HiOS and HiSecOS Products

  • Hirschmann Automation and Control GmbH, Belden Inc. EAGLE20/30 03.2.00 Hirschmann Automation and Control GmbH, Belden Inc. RSP RSPE RSPS RSPL MSP EES EES EESX GRS OS RED <= HiOS 07.0.02
    affected: mitigation “Hirschmann recommends updating HiOS products to Version 07.0.03 or higher and HiSecOS products to Version 03.3.00 or higher.” belden.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

Exploit prediction

1.65% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
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

  • Hirschmann Automation and Control GmbH, a division of Belden Inc. HiOS for the following devices RSP, RSPE, RSPS, RSPL, MSP, EES, EES, EESX, GRS, OS, RED
  • Hirschmann Automation and Control GmbH, a division of Belden Inc. HiSecOS for device EAGLE20/30

Classification

Weakness
  • CWE-12 ASP.NET Misconfiguration: Missing Custom Error Page
  • CWE-120 Buffer Copy without Checking Size of Input

References

Sources

Fencer Intel 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.