CVE-2024-5521
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 · uneditedTwo Cross-Site Scripting vulnerabilities have been discovered in Alkacon's OpenCMS affecting version 16, which could allow a user having the roles of gallery editor or VFS resource manager will have the permission to upload images in the .svg format containing JavaScript code. The code will be executed the moment another user accesses the image.
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 confidenceAlkacon OpenCMS 16 contains two stored XSS vulnerabilities in its image upload functionality. Users with gallery editor or VFS resource manager roles can upload .svg files containing embedded JavaScript code, which executes when other users view the uploaded image.
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= 16.0.0CVSS 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
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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 Alkacon OpenCMS installationCheck the application banner, about page, or look for 'Alkacon OpenCMS' string in application files. Check version file typically in the OpenCMS WAR or installation directory.Affected if The product is not Alkacon OpenCMS or the version is not 16.0.0
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Verify image upload functionality is accessibleCheck if the image upload module is enabled in the OpenCMS workplace configuration. Look for the gallery editor or VFS resource manager role assignments in the OpenCMS user management system.Affected if Image upload is disabled OR no users have gallery editor or VFS resource manager roles assigned
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Review uploaded .svg filesAccess the file system or OpenCMS VFS where images are stored (typically in the /sites/ or /resources/ directories). Search for .svg files.Affected if Any .svg files exist in the system that could contain embedded JavaScript code
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Inspect .svg file contents for malicious scriptsOpen and examine the contents of any uploaded .svg files. Look for script tags, event handlers (onclick, onload, etc.), or JavaScript: URIs within the SVG XML.Affected if Any .svg file contains script elements, event handler attributes, or other executable JavaScript content
A user is affected if they have Alkacon OpenCMS version 16.0.0 with the image upload feature enabled and users assigned gallery editor or VFS resource manager roles, with potentially malicious .svg files present in the system.
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 dataImplement strict validation of uploaded SVG files to strip or block JavaScript content, and configure Content Security Policy headers to prevent script execution from uploaded files.
- Consultation2.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2024-5521 — 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-2024-5521 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
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