CVE-2021-31505
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 · uneditedThis vulnerability allows attackers with physical access to escalate privileges on affected installations of Arlo Q Plus 1.9.0.3_278. Authentication is not required to exploit this vulnerability. The specific flaw exists within the SSH service. The device can be booted into a special operation mode where hard-coded credentials are accepted for SSH authentication. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root. Was ZDI-CAN-12890.
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 confidenceThe Arlo Q Plus device has a hardcoded credential vulnerability in its SSH service. When the device boots into a special operation mode, it accepts predefined credentials for SSH authentication without requiring legitimate credentials, allowing an attacker with physical access to gain root shell access and execute arbitrary code.
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= 1.9.0.3_278CVSS 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
- Physical
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:P/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 checksWork through these to decide whether this CVE applies to you.
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Identify the device modelLocate the physical Arlo Q Plus camera or access its web interface/admin panel to confirm the device is an Arlo Q Plus modelAffected if The device is not an Arlo Q Plus (different models are not affected by this specific CVE)
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Check the installed firmware versionAccess the device admin panel or use the Arlo mobile app to view the firmware version information. The version is typically displayed in Settings > Device Info > Firmware VersionAffected if The firmware version is exactly 1.9.0.3_278 (this is the only affected version for this CVE)
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Verify SSH service configurationAccess the device admin interface and check if SSH is enabled in the device settings or network configuration. Alternatively, attempt to connect to the device on port 22 to see if SSH is listeningAffected if SSH is enabled and accessible on the device (the vulnerability only applies when the SSH service is available)
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Check for special operation mode exposureDetermine if the device could potentially boot into or has been accessed via a special operation mode. This may be indicated by unusual boot sequences, debug ports, or documented service modes. Review device documentation or observe boot behavior for indicatorsAffected if The device supports or has a known special operation mode that can be triggered (the hardcoded credentials only function when the device is in this mode)
The environment is affected only if it is an Arlo Q Plus device running firmware version 1.9.0.3_278, with SSH enabled, and the device supports or can enter the special operation mode that accepts the hardcoded credentials.
Generated from the published advisory. Verify against your own configuration.
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 dataRestrict physical access to the device and contact Arlo for a firmware update that removes or secures the hardcoded credentials in the special operation mode.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-31505 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-31505 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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