CVE-2018-12027 Insecure Permissions in Phusion Passenger

High 8.8 Published 17 Jun 2018 Updated 5 Aug 2024

A local attacker can redirect application traffic by exploiting insecure Unix socket directory permissions, leading to information disclosure.

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

What is CVE-2018-12027?

CVE-2018-12027 is a high-severity vulnerability in n/a, published on 17 Jun 2018. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

An Insecure Permissions vulnerability in SpawningKit in Phusion Passenger 5.3.x before 5.3.2 causes information disclosure in the following situation: given a Passenger-spawned application process that reports that it listens on a certain Unix domain socket, if any of the parent directories of said socket are writable by a normal user that is not the application's user, then that non-application user can swap that directory with something else, resulting in traffic being redirected to a non-application user's process through an alternative Unix domain socket.

Weakness: CWE-732, CWE-200

Which versions are affected by CVE-2018-12027?

2 open source packages ship an affected version, including passenger. It affects 1 product.

Package	Affected	Fixed in
`passenger` RubyGems	From `5.3.0`	`5.3.2`
`passenger` RubyGems	From `5.3.0`	`5.3.2`

Products include Phusion Passenger.

How do I fix CVE-2018-12027?

Upgrade passenger to 5.3.2 or later.

Is CVE-2018-12027 being exploited?

There is no known exploitation of CVE-2018-12027 in the wild and no public exploit code.

Sources

Also known as GHSA-whfx-877c-5p28.