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OS Command InjectionWeakness · CWE-78

CVE-2026-30703

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
A command injection vulnerability exists in the web management interface of the WiFi Extender WDR201A (HW V2.1, FW LFMZX28040922V1.02). The adm.cgi endpoint improperly sanitizes user-supplied input provided to a command-related parameter in the sysCMD functionality.

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

Command injection vulnerability in the WiFi Extender WDR201A web management interface (adm.cgi). The sysCMD functionality fails to sanitize user-supplied input in a command-related parameter, allowing remote attackers to execute arbitrary OS commands on the device.

MitigationImplement network segmentation to isolate the device; block external access to the web management interface via firewall; if vendor firmware patch becomes available, apply it immediately. Consider replacing device if no patch is forthcoming.

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

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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 device model
    Access the device web interface or check device label/documentation to confirm the model is WDR201A
    Affected if Device model is WDR201A
  2. Determine firmware version
    Log into the web management interface and navigate to System or Status section to view the firmware version; compare against any vendor-advisory version ranges
    Affected if Firmware version falls within the affected version range (if known) or version cannot be determined
  3. Verify web management interface accessibility
    Attempt to access the device's web interface from the network using HTTP/HTTPS to confirm adm.cgi is reachable
    Affected if The web management interface (adm.cgi) is accessible on the device
  4. Confirm sysCMD functionality presence
    Send a request to adm.cgi and examine if the sysCMD parameter or functionality is present and operational in the interface
    Affected if sysCMD functionality is exposed and operational in the adm.cgi interface

User is affected if they have a WDR201A WiFi Extender with a vulnerable firmware version and the web management interface with sysCMD functionality is accessible on their network.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement network segmentation to isolate the device; block external access to the web management interface via firewall; if vendor firmware patch becomes available, apply it immediately. Consider replacing device if no patch is forthcoming.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2026-30703 in production — separate from our analysis above.

No notes yet

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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
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