Security readout for executives and security teams
Plain-English summary
Certain Hitachi ABB Power Grids protection and automation devices can be forced to reboot for about 60 seconds by an attacker on the IEC 61850 network. This is not a data-theft issue; it is an availability risk in operational technology environments where short outages may disrupt monitoring, protection, or control workflows.
Executive priority
Treat this as high priority for substations or grid automation environments where affected devices are reachable. Prioritize inventory, segmentation, and vendor-guided updates, especially where a 60-second device outage could affect protection, control, or operational continuity.
Technical view
CVE-2021-27196 is an improper input validation flaw triggered by a specially crafted IEC 61850 protocol sequence. It affects listed Relion, REB500, RTU500, FOX615, MSM, GMS600, and PWC600 products only when IEC 61850 interfaces are present. CVSS 3.1 is 7.5: network reachable, low complexity, no privileges, no user interaction, high availability impact.
Likely exposure
Exposure is limited to listed Hitachi ABB Power Grids products with IEC 61850 interfaces reachable by an attacker on that network. Highest concern is substations, grid automation, and industrial sites with flat or weakly segmented IEC 61850 networks.
Exploitation context
The CVE states an attacker needs IEC 61850 network access, knowledge to reproduce the attack, and IP addresses of IEC 61850 access points. The provided bundle does not cite active exploitation, and KEV status is false.
Researcher notes
Do not assume broad internet exposure; the stated prerequisite is access to the IEC 61850 network. Evidence identifies availability impact only. Some product ranges include version thresholds, but the bundle does not provide full advisory text, operational mitigations, or exploit observations.
Mitigation direction
- Inventory affected products and firmware versions against the CVE description.
- Confirm which assets expose IEC 61850 interfaces.
- Apply vendor updates or guidance from the listed ABB advisories where applicable.
- Restrict IEC 61850 network access to trusted engineering and operational hosts.
- Segment operational networks to limit reachability between untrusted systems and IEDs.
Validation and detection
- Check asset records for listed Relion, REB500, RTU500, FOX615, MSM, GMS600, and PWC600 products.
- Verify firmware versions against affected ranges and fixed-version thresholds in the CVE description.
- Confirm IEC 61850 interfaces are enabled only where operationally required.
- Review network controls for unauthorized paths to IEC 61850 access points.
- Monitor for unexpected device reboots or short availability drops on affected equipment.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-27196 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A8932&LanguageCode=en&DocumentPartId=&Action=LaunchCVE reference · x_refsource_CONFIRM
- https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A8936&LanguageCode=en&DocumentPartId=&Action=LaunchCVE reference · x_refsource_CONFIRM
- https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A8934&LanguageCode=en&DocumentPartId=&Action=LaunchCVE reference · x_refsource_CONFIRM
- https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A8937&LanguageCode=en&DocumentPartId=&Action=LaunchCVE reference · x_refsource_CONFIRM
- https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A9057&LanguageCode=en&DocumentPartId=&Action=LaunchCVE reference · x_refsource_CONFIRM
- https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A9058&LanguageCode=en&DocumentPartId=&Action=LaunchCVE reference · x_refsource_CONFIRM
- https://search.abb.com/library/Download.aspx?DocumentID=9AKK107991A9059&LanguageCode=en&DocumentPartId=&Action=LaunchCVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.