CVE-2021-47712
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 cryptography vulnerability in Kentico Xperience allows attackers to potentially manipulate URL hash values through existing hashing mechanisms. The hotfix introduces an additional security layer to prevent hash value reuse and potential exploitation.
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 cryptography vulnerability in Kentico Xperience allows attackers to potentially manipulate URL hash values through the existing hashing mechanism, enabling hash value reuse that could be exploited for unauthorized actions.
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<= 12.0.102CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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 the installed Kentico Xperience versionLocate the version information in the Kentico Xperience administration interface (typically under the Help > About section) or check the CMSVer assembly attribute in thebin folderAffected if The installed version is 12.0.102 or any earlier version within the 12.x line
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Confirm URL hash functionality is in useReview the application for usage of URL hash parameters (such as hash, sha, or similar query string parameters used for URL validation or signed URLs)Affected if URL hash or signature parameters are actively used in the application for validation or authorization purposes
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Inspect URL hashing configurationCheck web.config and any custom configuration files for settings related to URL signing, hash validation, or security token handlingAffected if Custom hash validation rules or URL signing mechanisms are configured without the additional security layer introduced in the hotfix
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Audit custom hashing implementationsSearch the codebase for custom implementations of hash computation or verification logic that handle URL parametersAffected if Custom hash computation methods exist that could allow hash value reuse without proper validation
The environment is affected if Kentico Xperience version 12.0.102 or lower is installed AND the URL hash/signing functionality is in use, as the vulnerability allows hash value reuse for unauthorized actions.
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 dataApply the Kentico Xperience hotfix which introduces an additional security layer to prevent hash value reuse and potential exploitation.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-47712 — 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-2021-47712 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
- No spam, self-promotion, credentials, or personal data