CVE-2019-17640
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 Eclipse Vert.x 3.4.x up to 3.9.4, 4.0.0.milestone1, 4.0.0.milestone2, 4.0.0.milestone3, 4.0.0.milestone4, 4.0.0.milestone5, 4.0.0.Beta1, 4.0.0.Beta2, and 4.0.0.Beta3, StaticHandler doesn't correctly processes back slashes on Windows Operating systems, allowing, escape the webroot folder to the current working directory.
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 StaticHandler in Eclipse Vert.x versions 3.4.x through 3.9.4 and 4.0.0 milestones/betas has a path traversal vulnerability specific to Windows. The handler fails to properly process backslashes in file paths, allowing attackers to escape the configured webroot folder and access files in the current working directory and potentially sensitive system files outside the intended static file directory.
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>= 3.4.0, <= 3.9.4= 4.0.0CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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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Identify Vert.x installation and versionInspect project build files (pom.xml, build.gradle, or build.gradle.kts) for org.eclipse.jetty:vertx-core dependency and note the version number. For deployed applications, check the classpath or lib folder for vertx-core jar files and their version metadata.Affected if The reported Vert.x version falls within 3.4.0 to 3.9.4 inclusive, or is 4.0.0 milestone/beta.
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Confirm operating system is WindowsCheck the operating system where the Vert.x application runs using 'systeminfo' on Windows or inspect environment variables (OS, WINDIR, or similar). This vulnerability is Windows-specific.Affected if The application runs on any Windows version, as the path traversal exploits backslash handling unique to Windows.
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Locate StaticHandler usage in codeSearch application source code for imports of io.vertx.ext.web.Router and look for occurrences of 'StaticHandler.create' or 'Router.route' with 'StaticHandler' as the handler. Also check for any route definitions serving static content.Affected if The application code explicitly uses StaticHandler to serve static files from a webroot directory.
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Inspect StaticHandler configurationReview the StaticHandler configuration in the code, specifically looking for setWebRoot or similar methods that define the static file directory. Identify the configured webroot path.Affected if StaticHandler is configured with a webroot directory, as the vulnerability allows escaping this directory.
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Check for backslash handling in requestsExamine URL request handling or proxy logs to see if incoming requests containing backslashes (URL-encoded as %5C) are accepted. If possible, test a request to a path like /..%5C..%5C/ to observe behavior.Affected if The server accepts and processes URLs containing backslashes without rejecting or normalizing them.
You are affected if you run Eclipse Vert.x versions 3.4.0 through 3.9.4 or 4.0.0 milestones on Windows, and your application uses the StaticHandler to serve static files.
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 · scopedUpgrade Eclipse Vert.x to version 3.9.5 or 4.0.0 or later which contains the corrected path handling. As a temporary workaround on Windows, implement input validation to reject URLs containing backslashes or conduct thorough review of static file serving configurations.
Vert.x 3.9.5 or later for 3.x branch; Vert.x 4.0.0 final or later for 4.x branch
- 1. Identify all Vert.x instances running versions 3.4.0 through 3.9.4 or 4.0.0 milestone/beta versions
- 2. Review the application for use of StaticHandler serving static files
- 3. Plan upgrade to fixed release (3.9.5 or later for 3.x branch, 4.0.0 final or later for 4.x branch)
- 4. Test the upgrade in a non-production environment, particularly on Windows deployments using StaticHandler
- 5. Deploy the upgraded version to production
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-17640 — 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-2019-17640 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
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