CVE-2021-23851
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 · uneditedA specially crafted TCP/IP packet may cause the camera recovery image web interface to crash. It may also cause a buffer overflow which could enable remote code execution. The recovery image can only be booted with administrative rights or with physical access to the camera and allows the upload of a new firmware in case of a damaged firmware.
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 confidenceA specially crafted TCP/IP packet sent to the camera's recovery image web interface triggers a buffer overflow that can crash the service or potentially enable remote code execution. The recovery image requires administrative credentials or physical access to the device to boot, limiting the attack surface but not eliminating it.
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= cpp7.3= cpp7.3= cpp7.3= cpp7.3= cpp7.3= cpp7.3= cpp7.3= cpp4= cpp7.3CVSS 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
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/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 camera modelAccess the camera's web interface or use network enumeration to determine the exact model name (e.g., Autodome Ip 4000i, Dinion Ip Bullet 5000, etc.)Affected if The model is one of: Autodome Ip 4000i, Autodome Ip 5000i, Autodome Ip Starlight 5000i, Autodome Ip Starlight 7000i, Dinion Ip 3000i, Dinion Ip Bullet 4000i, Dinion Ip Bullet 5000, or Dinion Ip Bullet 5000i
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Check the firmware versionIn the camera's web interface, navigate to the system information or firmware version page; alternatively, use the camera's API or configuration backup to retrieve the firmware build stringAffected if The firmware version string contains 'cpp7.3' (for most models) or 'cpp4' (for Dinion Ip Bullet 5000)
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Determine if recovery image is accessibleAttempt to access the recovery web interface by navigating to the camera's IP with a recovery-specific URL path or by checking if the device boots into recovery mode; verify network accessibility of port 80/443 on the deviceAffected if The recovery image web interface is network-accessible and responds to HTTP/HTTPS requests
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Check recovery mode access controlsReview whether administrative credentials are known or guessable, and verify physical security controls around the device to determine if recovery mode can be triggeredAffected if Administrative credentials for the recovery interface are compromised OR physical access to the device is not restricted
You are affected if you own one of the listed camera models AND the firmware shows version cpp7.3 (or cpp4 for Dinion Ip Bullet 5000) AND the recovery image web interface can be accessed via network or physical interaction with the device.
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 camera hardware and limit network access to recovery interfaces to trusted administrative networks only; apply vendor firmware updates when available.
- Consultation4.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,040.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-23851 — 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-2021-23851 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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- 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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