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Wrc 1167gst2 FirmwareOperating system · Elecom

CVE-2021-20863

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
OS command injection vulnerability in ELECOM 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 attackers to execute an arbitrary OS command with the root privilege 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 · high confidence

OS command injection vulnerability in multiple ELECOM router models allows an authenticated, network-adjacent attacker to execute arbitrary OS commands with root privileges via unspecified vectors, indicating improper input sanitization leading to command injection.

MitigationUpdate affected routers to the latest firmware version (v1.26+ for WRC-1167GST2/WRC-2533GST2 series, v1.53+ for WRC-2533GS2, v1.04+ for WRC-1750GS/WRC-1900GST/WRC-2533GST, v2.12+ for WRC-1750GSV); if updates unavailable, restrict network access to trusted users only and disable any remote management interfaces.

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 router model
    Log into the router web administration interface and locate the device information or status page to confirm the exact model number (Wrc-1167gst2, Wrc-1167gst2a, Wrc-1167gst2h, Wrc-2533gs2 B, Wrc-2533gs2 W, Wrc-1750gs, Wrc-1750gsv, or Wrc-1900gst).
    Affected if Model is one of the eight listed affected models.
  2. Check firmware version
    In the router web interface, navigate to the firmware version or system information page. Compare the installed firmware version against the affected ranges: 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 Firmware version is at or below the version limits listed for your specific model.
  3. Verify web management interface exposure
    Check the router's remote management or WAN access settings. Determine if the web administration interface is accessible from the WAN/internet side rather than only from the LAN.
    Affected if Remote management is enabled and the interface is accessible from untrusted networks.
  4. Assess authentication configuration
    Review the admin account settings. Confirm whether default credentials are still in use or if strong, unique passwords have been configured for router access.
    Affected if Default credentials remain unchanged or weak passwords are used, allowing easier authenticated attacker access.

Your environment is affected if you are running one of the eight listed ELECOM router models with firmware at or below the specified version limits, and the web management interface is accessible to untrusted network attackers.

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

Update affected routers to the latest firmware version (v1.26+ for WRC-1167GST2/WRC-2533GST2 series, v1.53+ for WRC-2533GS2, v1.04+ for WRC-1750GS/WRC-1900GST/WRC-2533GST, v2.12+ for WRC-1750GSV); if updates unavailable, restrict network access to trusted users only and disable any remote management interfaces.

Recommended fix Moderate confidence

ELECOM router firmware updated to latest available version (higher than vulnerable thresholds: >1.25, >1.52, >1.03, >2.11 depending on model)

  1. 1. Identify the exact model number of the ELECOM router from the affected product list (WRC-1167GST2, WRC-1167GST2A, WRC-1167GST2H, WRC-2533GS2-B, WRC-2533GS2-W, WRC-1750GS, WRC-1750GSV, WRC-1900GST, or related variants).
  2. 2. Access the router's web management interface using the admin credentials.
  3. 3. Navigate to the firmware update or system settings section.
  4. 4. Check the current firmware version displayed in the administration panel.
  5. 5. Download the latest firmware version from the official ELECOM support page at www.elecom.co.jp for the specific router model.
  6. 6. Upload and apply the new firmware file through the router's administration interface.
  7. 7. After the update completes, verify the new firmware version matches the latest available release.
  8. 8. Confirm the updated version is higher than the vulnerable threshold (e.g., >1.25 for WRC-1167GST2, >1.52 for WRC-2533GS2 models, >1.03 for WRC-1750GS/WRC-1900GST).
Caveat Factory reset may be recommended after firmware update; verify all custom configurations are backed up before proceeding

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

Fix this in Wrc 1167gst2 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

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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-2021-20863 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