CVE-2009-4875
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 · uneditedFCKeditor.Java 2.4 allows remote attackers to cause a denial of service (infinite loop) via a malformed request parameter that contains "ctrl" characters.
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 confidenceFCKeditor.Java 2.4 contains a denial of service vulnerability where malformed request parameters containing control characters trigger an infinite loop, causing the application to become unresponsive.
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= 2.4CVSS 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
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
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 FCKeditor.Java installationSearch for fckeditor-java JAR files or class files in your web application's WEB-INF/lib or lib directories, or check build configuration files (pom.xml, build.gradle) for FCKeditor dependenciesAffected if FCKeditor.Java library files are found in the application
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Identify installed versionExamine the JAR filename (e.g., fckeditor-java-2.4.jar), the manifest file inside the JAR, or check the dependency declaration in your build configuration for the exact version numberAffected if Version is exactly 2.4 (this is the only affected version)
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Verify web request handling is activeCheck if the FCKeditor servlet or filter is configured in web.xml and mapped to handle requests (look for org.fckeditor.* servlet or connector classes)Affected if FCKeditor request handling components are actively configured in the web application
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Confirm application is network accessibleVerify the web application is deployed and accessible over network (check server is running, application is deployed, and endpoints are reachable)Affected if The application is live and able to receive HTTP requests containing potentially malformed parameters
You are affected if FCKeditor.Java version 2.4 is installed and your application handles HTTP requests through the FCKeditor component, as malformed control characters in requests can trigger an infinite loop.
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 dataUpgrade to a patched version of FCKeditor or replace with a supported editor component, as this is an older version from 2009 with known issues.
- Consultation3.0 h
- Implementation6.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-4875 — 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-2009-4875 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