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Wrc 1167gst2 FirmwareOperating system · Elecom

CVE-2021-20859

HIGH · 8.0 CVSS v3.1 Published 2021-12-01
Fix available
A fix is available. Upgrade to after 2.11 or later.
See remediation →
82/100
Remediation priority · High
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
ELECOM LAN routers (WRC-1167GST2 firmware v1.25 and prior, WRC-1167GST2A firmware v1.25 and prior, WRC-1167GST2H firmware v1.25 and prior, WRC-2533GS2-B firmware v1.52 and prior, WRC-2533GS2-W firmware v1.52 and prior, WRC-1750GS firmware v1.03 and prior, WRC-1750GSV firmware v2.11 and prior, WRC-1900GST firmware v1.03 and prior, WRC-2533GST firmware v1.03 and prior, WRC-2533GSTA firmware v1.03 and prior, WRC-2533GST2 firmware v1.25 and prior, WRC-2533GST2SP firmware v1.25 and prior, WRC-2533GST2-G firmware v1.25 and prior, and EDWRC-2533GST2 firmware v1.25 and prior) allows a network-adjacent authenticated attacker to execute an arbitrary OS command via unspecified vectors.

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

Multiple ELECOM LAN router models contain an OS command injection vulnerability that allows an authenticated, network-adjacent attacker to execute arbitrary operating system commands. The specific attack vector and vulnerable function are not detailed in the available documentation.

MitigationContact ELECOM for available firmware updates to patch the command injection vulnerability. If no update is available, consider network segmentation or device replacement to reduce exposure.

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
Wrc 1167gst2 FirmwareOperating system
Affected:<= 1.25
Wrc 1167gst2a FirmwareOperating system
Affected:<= 1.25
Wrc 1167gst2h FirmwareOperating system
Affected:<= 1.25
Wrc 2533gs2 B FirmwareOperating system
Affected:<= 1.52
Wrc 2533gs2 W FirmwareOperating system
Affected:<= 1.52
Wrc 1750gs FirmwareOperating system
Affected:<= 1.03
Wrc 1750gsv FirmwareOperating system
Affected:<= 2.11
Wrc 1900gst FirmwareOperating system
Affected:<= 1.03

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
Adjacent
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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 router model
    Log into the router admin web interface and locate the device information or status page, or check the physical device label for the model name
    Affected if The model is one of: Wrc-1167gst2, Wrc-1167gst2a, Wrc-1167gst2h, Wrc-2533gs2-B, Wrc-2533gs2-W, Wrc-1750gs, Wrc-1750gsv, or Wrc-1900gst
  2. Determine the firmware version
    In the router admin interface, navigate to the system settings, status, or firmware information section to view the installed firmware version
    Affected if The firmware version cannot be determined or is not visible in the admin interface
  3. Compare firmware version against affected ranges
    Compare the installed firmware version to the affected version thresholds: Wrc-1167gst2/2a/2h <= 1.25, Wrc-2533gs2-B/W <= 1.52, Wrc-1750gs <= 1.03, Wrc-1750gsv <= 2.11, Wrc-1900gst <= 1.03
    Affected if The installed firmware version is at or below the affected threshold for that specific model
  4. Verify administrative access is possible
    Confirm you have valid administrator credentials to log into the router web management interface
    Affected if Administrative access is required for the command injection to be exploitable, as the attacker needs to be authenticated

You are affected if you are running any of the listed ELECOM router models with firmware at or below the specified version thresholds for your model.

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 a release after 2.11
Interim mitigation

Contact ELECOM for available firmware updates to patch the command injection vulnerability. If no update is available, consider network segmentation or device replacement to reduce exposure.

Recommended fix Moderate confidence

Latest firmware version available from ELECOM for each specific model (firmware > 1.25 for most models, > 1.52 for WRC-2533GS2, > 2.11 for WRC-1750GSV)

  1. 1. Identify the exact model number of your ELECOM router from the device label or web interface.
  2. 2. Navigate to the official ELECOM support page (www.elecom.co.jp) and locate the firmware download section for your specific router model.
  3. 3. Download the latest firmware version available for your model. Based on the vulnerability disclosure, firmware versions greater than the following should be sought: 1.26 or later for WRC-1167GST2/2A/2H, 1.53 or later for WRC-2533GS2-B/W, 1.04 or later for WRC-1750GS, 2.12 or later for WRC-1750GSV, 1.04 or later for WRC-1900GST.
  4. 4. Access the router's web management interface and locate the firmware update section (typically under Administration or System settings).
  5. 5. Upload the downloaded firmware file and initiate the update process.
  6. 6. Wait for the firmware to upload, flash, and for the router to reboot automatically.
  7. 7. After reboot, verify the firmware version in the web interface to confirm the update was successful.
  8. 8. As this vulnerability requires authentication, ensure the default administrator password has been changed to a strong, unique password.
Caveat Review ELECOM release notes for any changes to configuration requirements or feature modifications between versions

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

Fix this in Wrc 1167gst2 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,970
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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-2021-20859 in production — separate from our analysis above.

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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