CVE-2016-20023
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 CKSource CKFinder before 2.5.0.1 for ASP.NET, authenticated users could download any file from the server if the correct path to a file was provided.
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 confidenceCKFinder before 2.5.0.1 for ASP.NET contains an insecure direct object reference (IDOR) vulnerability allowing authenticated users to download arbitrary files from the server by providing file paths outside the intended upload directory scope.
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< 2.5.0.1CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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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Locate CKFinder installationSearch for ckfinder.js, ckfinder.aspx, or the CKFinder folder in your web application directory. Common paths include /ckfinder/, /admin/ckfinder/, or the root of ASP.NET applications.Affected if CKFinder files are found in the web application directory
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Identify CKFinder versionOpen the ckfinder.js or ckfinder.aspx file and look for a version string (e.g., var version = "2.5"; or similar). Alternatively, check the assembly version if using the DLL version, or look for a version.txt file in the CKFinder folder.Affected if Version is found to be lower than 2.5.0.1 or the version cannot be determined (older installations may not display version clearly)
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Verify ASP.NET handler is configuredCheck the web.config file for CKFinder handler registration. Look for lines containing 'CKFinder' in the handlers or modules section, typically mapping *.aspx requests to CKFinder.Affected if CKFinder HTTP handler is registered and active in the ASP.NET pipeline
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Confirm authentication is enabled for CKFinderReview web.config to determine if CKFinder is protected by authentication (forms, Windows, or other authentication methods). Check for <authorization> rules restricting CKFinder folders.Affected if CKFinder endpoint accepts authenticated requests (this is required for exploitation - the vulnerability affects authenticated users)
Your environment is affected if CKFinder for ASP.NET with version lower than 2.5.0.1 is installed and accessible 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.
dbcve · scoped2.5.0.1
Upgrade to CKFinder version 2.5.0.1 or later which implements proper path validation and access control checks to prevent unauthorized file access.
2.5.0.1 or later
- 1. Download CKFinder version 2.5.0.1 or later from the official CKEditor repository (ckeditor.com or download.cksource.com)
- 2. Create a complete backup of the current CKFinder installation directory
- 3. Replace all existing CKFinder files with the files from the new version
- 4. Verify that the version number reflects the upgrade (check About or version file)
- 5. Test that the path traversal vulnerability is remediated by attempting to access files outside the user directory - this should now be blocked
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 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 $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-20023 — 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-2016-20023 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