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Vulnerability record · CVE-2021-35533 · published 26 November 2021

CVE-2021-35533: Hitachienergy rtu500 firmware improper input validation vulnerability

Hitachienergy · Rtu500 Firmware

Improper Input Validation vulnerability in the APDU parser in the Bidirectional Communication Interface (BCI) IEC 60870-5-104 function of Hitachi Energy RTU500 series allows an attacker to cause the receiving RTU500 CMU of which the BCI is enabled to reboot when receiving a specially crafted message. By default, BCI IEC 60870-5-104 function is disabled (not configured). This issue affects: Hitachi Energy RTU500 series CMU Firmware version 12.0.* (all versions); CMU Firmware version 12.2.* (all versions); CMU Firmware version 12.4.* (all versions).

7.5 CVSS 3.1 High EPSS 0.95% · top 39.8% CWE-20 · Improper input validation
7.5CVSS 3.1 base score, v2 7.1
0.95%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

Improper Input Validation vulnerability in the APDU parser in the Bidirectional Communication Interface (BCI) IEC 60870-5-104 function of Hitachi Energy RTU500 series allows an attacker to cause the receiving RTU500 CMU of which the BCI is enabled to reboot when receiving a specially crafted message. By default, BCI IEC 60870-5-104 function is disabled (not configured). This issue affects: Hitachi Energy RTU500 series CMU Firmware version 12.0.* (all versions); CMU Firmware version 12.2.* (all versions); CMU Firmware version 12.4.* (all versions).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://search.abb.com/library/Download.aspx?DocumentID=8DBD000063&LanguageCode=en&DocumentPartId=&Action=Launch Vendor Advisory
https://search.abb.com/library/Download.aspx?DocumentID=8DBD000063&LanguageCode=en&DocumentPartId=&Action=Launch Vendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-35533), CISA KEV, FIRST EPSS (scores of 2026-10-11). This page is refreshed as NVD updates the record.