dbcve.org
Multilin B30 FirmwareOperating system · Ge

CVE-2021-27420

MEDIUM · 5.3 CVSS v3.1 Published 2022-03-23
Fix available
A fix is available. Upgrade to 8.10 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
GE UR firmware versions prior to version 8.1x web server task does not properly handle receipt of unsupported HTTP verbs, resulting in the web server becoming temporarily unresponsive after receiving a series of unsupported HTTP requests. When unresponsive, the web server is inaccessible. By itself, this is not particularly significant as the relay remains effective in all other functionality and communication channels.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The GE UR (Universal Relay) firmware versions prior to 8.1x contain a vulnerability in the embedded web server component. The web server task fails to properly handle receipt of unsupported HTTP verbs (non-standard HTTP request methods). When subjected to a series of unsupported HTTP requests, the web server enters a temporary unresponsive state, making the web management interface inaccessible. Other communication channels and relay functionality remain operational.

MitigationUpgrade GE UR firmware to version 8.1x or later to remediate this vulnerability. Coordinate upgrade with planned maintenance window as the web server may be temporarily unavailable during the update process.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Multilin B30 FirmwareOperating system
Affected:< 8.10
Multilin B90 FirmwareOperating system
Affected:< 8.10
Multilin C60 FirmwareOperating system
Affected:< 8.10
Multilin C70 FirmwareOperating system
Affected:< 8.10
Multilin C95 FirmwareOperating system
Affected:< 8.10
Multilin D30 FirmwareOperating system
Affected:< 8.10
Multilin D60 FirmwareOperating system
Affected:< 8.10
Multilin F35 FirmwareOperating system
Affected:< 8.10

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the GE Multilin relay model
    Locate the relay model number on the physical device label or check the system configuration. Confirm it is one of: B30, B90, C60, C70, C95, D30, D60, or F35.
    Affected if The relay model is one of the listed affected models.
  2. Check the installed firmware version
    Access the relay via Enervista UR Setup software, the front panel menu (under Device Information or System Status), or the web interface if accessible. Record the firmware version number.
    Affected if The firmware version is less than 8.10 (for example, 7.x or 8.0x).
  3. Verify the embedded web server is enabled
    Check the relay configuration through Enervista UR Setup or the web interface settings. Confirm that the HTTP web server service is configured as enabled.
    Affected if The web server is enabled and the firmware version is below 8.10.

If you have a B30, B90, C60, C70, C95, D30, D60, or F35 relay with firmware version below 8.10 and the embedded web server is enabled, your environment is affected by this vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.10 or later
Fixed in 8.10
Interim mitigation

Upgrade GE UR firmware to version 8.1x or later to remediate this vulnerability. Coordinate upgrade with planned maintenance window as the web server may be temporarily unavailable during the update process.

Recommended fix Moderate confidence

Firmware 8.10 or later (8.1x series)

  1. Identify the specific Multilin model (B30, B90, C60, C70, C95, D30, D60, or F35) that needs remediation
  2. Determine the current firmware version by accessing the device through its web interface or management console
  3. Navigate to the GE Grid Solutions support website and locate the firmware download section for the specific model
  4. Download firmware version 8.10 or later (8.1x series) from the official GE Grid Solutions site
  5. Review the firmware upgrade instructions specific to the device model
  6. Upload and apply the new firmware following the documented upgrade procedure
  7. After upgrade completes, verify the web server responds correctly to HTTP requests
  8. Confirm the new firmware version is displayed correctly in the device interface
Caveat Standard firmware upgrade risks apply - ensure proper backup of configuration and follow upgrade procedure to avoid device interruption

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Multilin B30 Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,840
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,144.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-27420 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-27420 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data