---
title: "CVE-2018-12027\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2018-12027?format=md
keywords: index, follow
---

# CVE-2018-12027

Publication date 17 June 2018

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**8.8 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2018-12027?format=md#impact-score)

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## 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.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2018-12027?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| passenger | 22.04 LTS jammy | Not affected |
| 21.10 impish | Not affected |
| 21.04 hirsute | Ignored end of life |
| 20.10 groovy | Ignored end of life |
| 20.04 LTS focal | Not affected |
| 19.10 eoan | Ignored end of life |
| 19.04 disco | Ignored end of life |
| 18.10 cosmic | Ignored end of life |
| 18.04 LTS bionic | Not affected |
| 17.10 artful | Ignored end of life |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not in release |
| ruby-passenger | 22.04 LTS jammy | Not in release |
| 21.10 impish | Not in release |
| 21.04 hirsute | Not in release |
| 20.10 groovy | Not in release |
| 20.04 LTS focal | Not in release |
| 19.10 eoan | Not in release |
| 19.04 disco | Not in release |
| 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not in release |
| 17.10 artful | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Notes

---

### [rodrigo-zaiden](https://launchpad.net/~rodrigo-zaiden)

xenial, bionic, focal and impish have version 5.0.x and are
not affected because the issue was introduced in 5.3.0, with a major
overhaul in SpawningKit.

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.8 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | Low |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.8 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12027)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-12027)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-12027)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-12027)

### Other references

* <https://blog.phusion.nl/2018/06/12/passenger-5-3-2-various-security-fixes/>
* <https://blog.phusion.nl/passenger-5-3-2>
* <https://www.cve.org/CVERecord?id=CVE-2018-12027>