CVE-2021-31226
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 · uneditedAn issue was discovered in HCC embedded InterNiche 4.0.1. A potential heap buffer overflow exists in the code that parses the HTTP POST request, due to lack of size validation. This vulnerability requires the attacker to send a crafted HTTP POST request with a URI longer than 50 bytes. This leads to a heap overflow in wbs_post() via an strcpy() call.
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 confidenceHeap buffer overflow in HCC embedded InterNiche 4.0.1 HTTP POST request parser. The wbs_post() function uses strcpy() without validating the URI length, allowing a heap overflow when the URI exceeds 50 bytes.
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= 4.0.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Confirm InterNiche versionIdentify the version of HCC Embedded InterNiche library in your environment. Check library files, build manifests, or software bills of materials (SBOM) for InterNiche version 4.0.1.Affected if The installed version is exactly InterNiche 4.0.1
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Verify HTTP server module is enabledDetermine if the HTTP server module (commonly referred to as wbs or web server) is compiled and enabled in your firmware or application. Check build configuration files for HTTP server inclusion.Affected if HTTP server module is present and enabled in the build
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Check for POST request handlingInspect your application code to determine if HTTP POST requests are handled. Review web server initialization and URI handling code paths for POST method processing.Affected if HTTP POST requests are processed by the web server
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Inspect wbs_post function for unbounded copyLocate the wbs_post() function in your source code or binary. Examine whether it contains a strcpy() call copying the URI without length validation or bounds checking.Affected if The wbs_post() function uses strcpy() to copy the URI without length validation
Your environment is affected if you are running InterNiche version 4.0.1 with the HTTP server and POST request handling enabled, and the wbs_post() function contains an unbounded strcpy() copying the URI without validation.
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 unsafe strcpy() call in wbs_post() with a bounds-checked function (e.g., strncpy, strlcpy) and add explicit size validation before copying the URI. Consider upgrading to a patched version of InterNiche if available.
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-31226 — 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-2021-31226 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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