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MEDIUM4.8

GHSA-53jx-vvf9-4x38

StaticHandler disclosure of classpath resources on Windows when mounted on a wildcard route

Quick fix

GHSA-53jx-vvf9-4x38 — io.vertx:vertx-web: upgrade to the fixed version with the command below.

# pom.xml: bump <version>4.3.8</version> for io.vertx:vertx-web

Details

### Summary

When running vertx web applications that serve files using `StaticHandler` on Windows Operating Systems and Windows File Systems, if the mount point is a wildcard (`*`) then an attacker can exfiltrate any class path resource.

### Details When computing the relative path to locate the resource, in case of wildcards, the code:

https://github.com/vert-x3/vertx-web/blob/62c0d66fa1c179ae6a4d57344631679a2b97e60f/vertx-web/src/main/java/io/vertx/ext/web/impl/Utils.java#L83

returns the user input (without validation) as the segment to lookup. Even though checks are performed to avoid escaping the sandbox, given that the input was not sanitized `\` are not properly handled and an attacker can build a path that is valid within the classpath.

### PoC

https://github.com/adrien-aubert-drovio/vertx-statichandler-windows-traversal-path-vulnerability

Are you affected?

Enter the version of the package you're using.

Affected packages

Maven/io.vertx:vertx-web
Introduced in: 4.0.0Fixed in: 4.3.8
Fix# pom.xml: bump <version>4.3.8</version> for io.vertx:vertx-web

References