CVE-2018-18315
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 · uneditedcom/mossle/cdn/CdnController.java in lemon 1.9.0 allows attackers to upload arbitrary files because the copyMultipartFileToFile method in CdnUtils only checks for a ../ substring, and does not validate the file type and spaceName parameter.
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 confidenceThe CdnController.java in lemon 1.9.0 contains an arbitrary file upload vulnerability where the copyMultipartFileToFile method in CdnUtils only checks for '../' substring in the filename but fails to validate file types or the spaceName parameter, allowing attackers to upload malicious files to the server.
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= 1.9.0CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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 lemon installation and versionLocate the lemon web application deployment and check the version indicator (such as version manifest, pom.xml, or version file in the installation directory). Compare the installed version to the affected version 1.9.0.Affected if The installed lemon version is exactly 1.9.0.
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Locate the vulnerable CdnController componentSearch the deployed application for the file CdnController.java or its compiled class CdnController.class, or for CdnUtils.java/CdnUtils.class containing the copyMultipartFileToFile method.Affected if The CdnController or CdnUtils component with the copyMultipartFileToFile method is present in the deployment.
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Verify the CDN file upload endpoint is exposedCheck if the CdnController servlet endpoint for file upload is mapped and accessible (typically at a URL path containing '/cdn/' or '/file/upload').Affected if The CDN upload endpoint is accessible without additional authentication or with weak authentication.
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Inspect the file type validation logicExamine the CdnUtils.copyMultipartFileToFile method code to confirm it lacks proper file type validation (no allowlist check for permitted extensions/content-types).Affected if The code shows no file type allowlist validation is implemented in the upload method.
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Check the spaceName parameter handlingReview the CdnController code to verify whether the spaceName parameter is validated against expected values before being used in file operations.Affected if The spaceName parameter is used without validation against an allowlist of permitted values.
You are affected if lemon version 1.9.0 is deployed and the CdnController file upload endpoint is accessible without proper file type or spaceName validation.
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 allowlist-based file type validation, validate the spaceName parameter against expected values, and store uploaded files outside webroot with random filenames to prevent arbitrary file upload attacks.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-18315 — 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-2018-18315 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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