CVE-2018-12940
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 · uneditedUnrestricted file upload vulnerability in "op/op.UploadChunks.php" in SeedDMS (formerly LetoDMS and MyDMS) before 5.1.8 allows remote attackers to execute arbitrary code by uploading a file with an executable extension specified by the "qqfile" parameter. This allows an authenticated attacker to upload a malicious file containing PHP code to execute operating system commands to the web root of the application.
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 confidenceUnrestricted file upload vulnerability in SeedDMS allows authenticated users to upload files with executable extensions (e.g., .php) via the qqfile parameter to the web root, enabling arbitrary PHP code execution and OS command injection.
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< 5.1.8CVSS 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
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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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Confirm SeedDMS installation and versionLocate the SeedDMS installation directory and check the version file or software release information (often in a version.php file, README, or admin interface)Affected if The installed version is below 5.1.8 (e.g., 5.1.7, 5.1.6, earlier releases)
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Identify the upload functionality endpointExamine the web application's form handling for file uploads, specifically look for parameters named 'qqfile' used in the upload mechanismAffected if The application processes file uploads via a 'qqfile' parameter without proper extension filtering
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Verify upload storage locationCheck the SeedDMS configuration to determine where uploaded files are stored relative to the web server document rootAffected if Uploaded files are stored within the web root (document root) rather than in an external directory outside the web-accessible path
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Test for executable extension filteringIf you have an authenticated test account, attempt to upload a test file with a .php extension (or review the code/validation logic for file type checks)Affected if The system accepts and stores files with executable extensions like .php, .phtml, or .php5 without blocking them
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Confirm authentication requirement for uploadVerify whether the file upload feature requires authentication or is accessible to any userAffected if The upload endpoint accepts requests from authenticated users (the vulnerability requires an authenticated session)
You are affected if SeedDMS version is below 5.1.8, the upload functionality with the 'qqfile' parameter is accessible to authenticated users, and uploaded files with executable extensions can be stored within the web root.
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 data5.1.8
Update to SeedDMS version 5.1.8 or later; alternatively, implement strict file type validation, reject executable extensions, and store uploads outside the web root with disabled script execution.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 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 $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-12940 — 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-2018-12940 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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