TYPO3CMS
CVE-2021-21358
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 · uneditedTYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that the Form Designer backend module of the Form Framework is vulnerable to cross-site scripting. A valid backend user account with access to the form module is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1.
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 confidenceTYPO3 Form Framework's Form Designer backend module is vulnerable to cross-site scripting (XSS). An authenticated backend user with access to the form module can inject malicious scripts through Form Designer, which get executed when other users view the affected forms or the form designer interface.
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
TYPO3CMS
>= 10.2.0, < 10.4.14>= 11.0.0, < 11.1.1CVSS 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
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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 TYPO3 versionCheck the installed TYPO3 version by reviewing the composer.json file in the web root, or access the TYPO3 backend and navigate to Admin Tools > About to view the version number.Affected if The installed version falls within 10.2.0 - 10.4.13 or 11.0.0 - 11.1.0.
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Verify Form Designer module is accessibleLog into the TYPO3 backend and check if the Form module appears in the main navigation. The vulnerability requires the Form Designer module to be accessible to the user.Affected if The Form module is installed and accessible to backend users.
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Check backend user permissions to Form moduleNavigate to Admin Tools > Users > Backend Users groups (or access list) and inspect which user groups have access to the Form module (tx_form).Affected if Any backend user group grants access to the Form Designer module.
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Inspect existing forms for suspicious contentIn the TYPO3 backend, open the Form module and list all existing forms. Check form configurations, labels, and element names for unusual script tags, event handlers (onclick, onload, etc.), or encoded JavaScript payloads.Affected if Any form contains JavaScript code embedded in form element labels, names, or configuration values.
A user is affected if their TYPO3 version is between 10.2.0 and 10.4.13 or between 11.0.0 and 11.1.0, and the Form Designer module is accessible to backend users.
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 data10.4.1411.1.1
Upgrade TYPO3 to version 10.4.14 or 11.1.1 or later to receive the security patch. Alternatively, restrict the Form Designer module permissions to only highly trusted backend users until the upgrade can be performed.
Fix this in TYPO3
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 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 $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21358 — 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-2021-21358 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