GitLabApplication
CVE-2021-22220
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 has been discovered in GitLab affecting all versions starting with 13.10. GitLab was vulnerable to a stored XSS in blob viewer of notebooks.
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 confidenceGitLab versions 13.10 and later contain a stored cross-site scripting (XSS) vulnerability in the blob viewer component of notebooks. Attackers can inject malicious JavaScript that executes when users view notebook content, allowing session hijacking or data theft.
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
GitLabApplication
>= 13.10, <= 13.10.5>= 13.11, <= 13.11.5>= 13.12, <= 13.12.2CVSS 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 installed GitLab versionRun `sudo gitlab-rake gitlab:version` or check the GitLab admin panel under Help > Version to determine the exact version numberAffected if The version is 13.10.0 through 13.10.5, 13.11.0 through 13.11.5, or 13.12.0 through 13.12.2
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Confirm notebook feature is in useCheck if any notebooks (.ipynb files) have been uploaded or created in any project by navigating to a project and looking for notebook files in the repository browser, or query the database for notebook records in the notes table where noteable_type is Noteable::SnippetAffected if Notebooks exist in the environment and users can view them through the blob viewer
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Inspect notebook content for injected scriptsExamine the raw content of notebook files in the repository or review the snippets database table for any script tags, javascript: URIs, or event handler attributes in the JSON structure of .ipynb filesAffected if Notebook content contains unsanitized script tags or JavaScript event handlers that could execute when rendered in the blob viewer
You are affected if your GitLab version falls within 13.10.0-13.10.5, 13.11.0-13.11.5, or 13.12.0-13.12.2 AND notebooks are accessible to users who could view malicious content in the blob viewer.
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 dataUpgrade GitLab to the latest available version or to a patched version for your release branch. Review notebook blob viewer content for any suspicious injected scripts.
Fix this in GitLab
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 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 $2,560.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-22220 — 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-2021-22220 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