What is the CVSS score of CVE-2021-27196?

CVE-2021-27196 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 1.6%.

Reb500 Firmware CVE-2021-27196

HIGH

Improper Input Validation (CWE-20)

2021-06-14 cve@mitre.org

Information Disclosure Abb Reb500 Firmware Relion 650 Firmware Relion 670 Firmware Relion Sam600 Io Firmware Rtu500 Firmware Fox615 Tego1 Firmware Modular Switchgear Monitoring Firmware Gms600 Firmware Pwc600 Firmware Hitachienergy

7.5

CVSS 3.1 · NVD

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Vulnerability Assessment

Weakness	CWE CWE-20 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V2 - Validation and Business Logic Input validation, allowlisting
Impact	CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required.
Exploit ScenarioDerived	This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the high-severity affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 1.6% exploitation probability (EPSS)

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AnalysisAI

Improper Input Validation vulnerability in Hitachi ABB Power Grids Relion 670 Series, Relion 670/650 Series, Relion 670/650/SAM600-IO, Relion 650, REB500, RTU500 Series, FOX615 (TEGO1), MSM, GMS600,. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

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Technical ContextAI · show details

This vulnerability is classified under CWE-20. Improper Input Validation vulnerability in Hitachi ABB Power Grids Relion 670 Series, Relion 670/650 Series, Relion 670/650/SAM600-IO, Relion 650, REB500, RTU500 Series, FOX615 (TEGO1), MSM, GMS600, PWC600 allows an attacker with access to the IEC 61850 network with knowledge of how to reproduce the attack, as well as the IP addresses of the different IEC 61850 access points (of IEDs/products), to force the device to reboot, which renders the device inoperable for approximately 60 seconds. This vulnerability affects only products with IEC 61850 interfaces. This issue affects: Hitachi ABB Power Grids Relion 670 Series 1.1; 1.2.3 versions prior to 1.2.3.20; 2.0 versions prior to 2.0.0.13; 2.1; 2.2.2 versions prior to 2.2.2.3; 2.2.3 versions prior to 2.2.3.2. Hitachi ABB Power Grids Relion 670/650 Series 2.2.0 versions prior to 2.2.0.13. Hitachi ABB Power Grids Relion 670/650/SAM600-IO 2.2.1 versions prior to 2.2.1.6. Hitachi ABB Power Grids Relion 650 1.1; 1.2; 1.3 versions prior to 1.3.0.7. Hitachi ABB Power Grids REB500 7.3; 7.4; 7.5; 7.6; 8.2; 8.3. Hitachi ABB Power Grids RTU500 Series 7.x version 7.x and prior versions; 8.x version 8.x and prior versions; 9.x version 9.x and prior versions; 10.x version 10.x and prior versions; 11.x version 11.x and prior versions; 12.x version 12.x and prior versions. Hitachi ABB Power Grids FOX615 (TEGO1) R1D02 version R1D02 and prior versions. Hitachi ABB Power Grids MSM 2.1.0 versions prior to 2.1.0. Hitachi ABB Power Grids GMS600 1.3.0 version 1.3.0 and prior versions. Hitachi ABB Power Grids PWC600 1.0 versions prior to 1.0.1.4; 1.1 versions prior to 1.1.0.1. Affected products include: Hitachienergy Relion 670 Firmware, Hitachienergy Relion 650 Firmware, Hitachienergy Relion Sam600-Io Firmware, Hitachienergy Rtu500 Firmware, Hitachienergy Reb500 Firmware. Version information: prior to 1.2.3.20.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.5 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

DescriptionNVD

Improper Input Validation vulnerability in Hitachi ABB Power Grids Relion 670 Series, Relion 670/650 Series, Relion 670/650/SAM600-IO, Relion 650, REB500, RTU500 Series, FOX615 (TEGO1), MSM, GMS600, PWC600 allows an attacker with access to the IEC 61850 network with knowledge of how to reproduce the attack, as well as the IP addresses of the different IEC 61850 access points (of IEDs/products), to force the device to reboot, which renders the device inoperable for approximately 60 seconds. This vulnerability affects only products with IEC 61850 interfaces. This issue affects: Hitachi ABB Power Grids Relion 670 Series 1.1; 1.2.3 versions prior to 1.2.3.20; 2.0 versions prior to 2.0.0.13; 2.1; 2.2.2 versions prior to 2.2.2.3; 2.2.3 versions prior to 2.2.3.2. Hitachi ABB Power Grids Relion 670/650 Series 2.2.0 versions prior to 2.2.0.13. Hitachi ABB Power Grids Relion 670/650/SAM600-IO 2.2.1 versions prior to 2.2.1.6. Hitachi ABB Power Grids Relion 650 1.1; 1.2; 1.3 versions prior to 1.3.0.7. Hitachi ABB Power Grids REB500 7.3; 7.4; 7.5; 7.6; 8.2; 8.3. Hitachi ABB Power Grids RTU500 Series 7.x version 7.x and prior versions; 8.x version 8.x and prior versions; 9.x version 9.x and prior versions; 10.x version 10.x and prior versions; 11.x version 11.x and prior versions; 12.x version 12.x and prior versions. Hitachi ABB Power Grids FOX615 (TEGO1) R1D02 version R1D02 and prior versions. Hitachi ABB Power Grids MSM 2.1.0 versions prior to 2.1.0. Hitachi ABB Power Grids GMS600 1.3.0 version 1.3.0 and prior versions. Hitachi ABB Power Grids PWC600 1.0 versions prior to 1.0.1.4; 1.1 versions prior to 1.1.0.1.

Threat Intelligence Overview

EPSS Score

1.6%

Top 27% exploitable

Data Quality

2 sources

Confidence: Low

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 1.6%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +2

CVSS: +38

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.