CVE-2021-4228
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 · uneditedUse of hard-coded TLS certificate by default allows an attacker to perform Man-in-the-Middle (MitM) attacks even in the presence of the HTTPS connection. This issue affects: Lanner Inc IAC-AST2500A standard firmware version 1.00.0.
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 confidenceThe IAC-AST2500A firmware ships with a hard-coded/default TLS certificate and corresponding private key embedded in the firmware image. Because the same certificate is used across all devices, any attacker who extracts or obtains this certificate can impersonate the server and perform Man-in-the-Middle attacks against HTTPS connections, intercepting or modifying encrypted traffic.
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= 1.00.0CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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 firmware versionCheck the installed firmware version on the IAC-AST2500A device through the device management interface or by reading the firmware image metadataAffected if The firmware version is exactly 1.00.0 (Lannerinc Iac Ast2500 Firmware)
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Extract embedded certificate from firmwareExtract the firmware image (e.g., via firmware extraction tools) and search for PEM-encoded certificate files (.cer, .crt, .pem) or binary certificate blobs within the firmware imageAffected if A TLS certificate is found embedded in the firmware binary
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Compare device certificate to known defaultExtract the certificate currently in use on the device and compare its modulus or fingerprint against publicly known default certificates for this firmwareAffected if The device certificate matches a publicly documented default certificate that ships with the firmware
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Verify unique certificate per deviceObtain certificates from multiple devices (if available) and compare their serial numbers, public keys, or fingerprintsAffected if Multiple devices share identical certificates, indicating the same default certificate is in use across the device fleet
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Check for custom certificate deploymentInspect the device configuration or management interface to determine if a custom, unique certificate has been provisioned by the administratorAffected if No custom certificate has been configured and the device is using the factory default certificate
A user is affected if they are running IAC-AST2500A firmware version 1.00.0 and the device is using the hard-coded default TLS certificate instead of a unique, properly signed certificate per 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 dataReplace the hard-coded certificate with a unique, properly signed certificate per device, implement certificate validation, and provide a secure mechanism for certificate rotation in future firmware updates.
- Consultation4.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,960.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-4228 — 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-2021-4228 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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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.
- 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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