Joomla\!Application · Joomla
CVE-2018-6377
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 · uneditedIn Joomla! before 3.8.4, inadequate input filtering in com_fields leads to an XSS vulnerability in multiple field types, i.e., list, radio, and checkbox
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 confidenceJoomla! before version 3.8.4 contains an XSS vulnerability in the com_fields component due to inadequate input filtering. Attackers can inject malicious scripts through list, radio, and checkbox field types by not properly sanitizing user-supplied input.
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
< 3.8.4CVSS 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:3.0/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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Identify Joomla versionLog in to the Joomla administrator panel and navigate to System > System Information, or check the libraries/cms.php file for the VERSION constantAffected if The installed version is below 3.8.4
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Confirm com_fields component is presentNavigate to Components > Custom Fields in the Joomla administrator panel, or check for the com_fields directory in the /components/ folderAffected if The com_fields component exists and is accessible in the installation
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Check for list, radio, or checkbox field typesIn the administrator panel, go to Components > Custom Fields > Fields and review the field types assigned to any custom field groupsAffected if Any custom fields are configured with type list, radio, or checkbox
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Inspect field configuration for unsanitized inputEdit each list, radio, and checkbox field configuration and examine the Default Value or Options fields for any user-supplied values that may contain script tags or HTMLAffected if The field options contain raw user input without apparent sanitization or contain suspicious characters like <script> tags
A user is affected if their Joomla installation is version 3.8.4 or earlier, the com_fields component is active, and custom fields of type list, radio, or checkbox exist with unsanitized user-supplied values.
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 data3.8.4
Upgrade Joomla! to version 3.8.4 or later. If immediate upgrade is not possible, implement input validation/sanitization on all field inputs in com_fields, particularly for list, radio, and checkbox field types.
Fix this in Joomla\!
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-2018-6377 — 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-2018-6377 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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- 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