CVE-2018-12542 Eclipse Vert.x does not properly neutralize '' (forward slashes) sequences that can resolve to an external location

Critical 9.8 Published 10 Oct 2018 Updated 5 Aug 2024

Attackers can read files outside the restricted directory on Windows systems using the StaticHandler in Eclipse Vert.x.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2018-12542?

CVE-2018-12542 is a critical path traversal vulnerability in The Eclipse Foundation Eclipse Vert.x, published on 10 Oct 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-22

Which versions are affected by CVE-2018-12542?

2 open source packages ship an affected version, including io.vertx:vertx-web. It affects 1 product.

Package	Affected	Fixed in
`io.vertx:vertx-web` Maven	From `3.0.0`	`3.5.4`
`io.vertx:vertx-web` Maven	From `3.0.0`	`3.5.4`

Products include Eclipse Vert.x.

How do I fix CVE-2018-12542?

Upgrade io.vertx:vertx-web to 3.5.4 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2018-12542 being exploited?

There is no known exploitation of CVE-2018-12542 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Sources

Also known as GHSA-h39x-m55c-v55h.