CVE-2023-28819
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 · uneditedConcrete CMS (previously concrete5) versions 8.5.12 and below, 9.0.0 through 9.0.2 is vulnerable to Stored XSS in uploaded file and folder names.
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 confidenceStored Cross-Site Scripting (XSS) vulnerability in Concrete CMS where malicious JavaScript code can be embedded in file and folder names during upload. When other users view or interact with these files/folders through the CMS interface, the persisted script executes in their browser context.
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< 9.1.0CVSS 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 Concrete CMS versionLocate the version number in the CMS dashboard (typically under Dashboard > System Information > Version) or check the composer.json file in the installation root directoryAffected if The installed version is lower than 9.1.0 (e.g., 9.0.x, 8.5.x, or earlier)
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Confirm file manager is accessibleLog into the CMS as an authenticated user and navigate to the File Manager (Dashboard > Files > File Manager). Verify you can upload files or create foldersAffected if The file manager functionality is enabled and users have upload/create permissions
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Review file names for potential XSS payloadsIn the File Manager interface, browse through uploaded files. Look for file names containing script tags (<script>), javascript: URLs, event handlers (onload, onerror, onclick), or unusual encoding patternsAffected if Any file names in the system contain executable JavaScript code or suspicious patterns that could indicate exploitation
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Inspect folder names for injected scriptsIn the File Manager, expand folder structures and examine folder names for script tags, event handlers, or other XSS patternsAffected if Any folder names contain persisted script content that could execute when viewed
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Check browser console for script errorsAs a logged-in user, navigate through the File Manager and open browser developer tools (F12). Monitor the Console tab for JavaScript errors or unexpected script executions triggered by file/folder namesAffected if JavaScript executes unexpectedly when viewing file or folder listings
A user is affected if their Concrete CMS installation is version 9.1.0 or higher AND the File Manager contains file or folder names with embedded malicious JavaScript that could execute in other users' browsers.
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.
dbcve · scoped9.1.0
Upgrade to a patched version of Concrete CMS (9.1.0+ for 9.x branch, 8.5.13+ for 8.x branch) and implement server-side input sanitization/validation on file and folder name fields.
Concrete CMS 9.1.0 or later
- Create a complete backup of your database and all site files before proceeding
- Download Concrete CMS version 9.1.0 or later from the official website (www.concretecms.org)
- Extract the new version files to your server, replacing the existing installation
- Run the upgrade process via the web browser by accessing your site or via command line if available
- Clear any caching mechanisms after the upgrade
- Verify the XSS vulnerability is resolved by attempting to upload files/folders with script content in the name
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-28819 — 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-2023-28819 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