Joomla\!Application · Joomla
CVE-2021-23130
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 Joomla! 2.5.0 through 3.9.24. Missing filtering of feed fields could lead to xss issues.
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 confidenceA Cross-Site Scripting (XSS) vulnerability in Joomla! CMS versions 2.5.0 through 3.9.24 stems from missing input filtering on feed fields, allowing attackers to inject malicious scripts via RSS/Atom feeds that execute in authenticated users' browsers when viewing feed content.
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
Joomla\!Application
>= 2.5.0, < 3.9.25CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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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Check your Joomla CMS versionNavigate to the Joomla administrator dashboard and locate the version information typically found in the Help menu > System Information, or check the libraries/cms/version.php file. Alternatively, view the meta generator tag in the page source of your site frontend.Affected if The installed version is >= 2.5.0 and < 3.9.25
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Identify if RSS/Atom feed functionality is in useCheck your Joomla site for enabled feed components or modules. This includes checking for the built-in Syndication (Feed) component, any third-party feed extensions, or custom feed integrations that pull external RSS/Atom content into the site.Affected if RSS or Atom feed functionality is enabled and displaying feed content on the site
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Verify feed content handlingInspect the feed display pages or modules on your site. Look for any areas where feed titles, descriptions, or other feed metadata are rendered to users, particularly in administrator-facing feed previews or public feed displays.Affected if Feed fields (titles, descriptions, links) from external or internal feeds are being displayed to authenticated users without visible sanitization indicators
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Check for feed-related administrator accessReview user accounts with access to the Feed component in Joomla (Components > Feeds) or any third-party feed management extensions. Identify if low-privileged or compromised accounts can create or modify feed entries.Affected if Authenticated users with access to feed management exist in the system and can create or modify feed content
Your environment is affected if you are running Joomla version 2.5.0 through 3.9.24 AND you have RSS/Atom feed functionality enabled that displays feed content to authenticated 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 data3.9.25
Upgrade Joomla to a version newer than 3.9.24 or apply the available security patch that implements proper input sanitization on feed field data.
Fix this in Joomla\!
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 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 $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-23130 — 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-2021-23130 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