---
title: "CVE-2018-12368\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-2018-12368?format=md
keywords: index, follow
---

# CVE-2018-12368

Publication date 18 October 2018

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**8.1 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2018-12368?format=md#impact-score)

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## Description

Windows 10 does not warn users before opening executable files with the
SettingContent-ms extension even when they have been downloaded from the
internet and have the "Mark of the Web." Without the warning, unsuspecting
users unfamiliar with this new file type might run an unwanted executable.
This also allows a WebExtension with the limited downloads.open permission
to execute arbitrary code without user interaction on Windows 10 systems.
\*Note: this issue only affects Windows operating systems. Other operating
systems are unaffected.\*. This vulnerability affects Thunderbird < 60,
Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox <
61.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2018-12368?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not in release |
| mozjs38 | 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| mozjs52 | 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| thunderbird | 18.04 LTS bionic | Not affected |
| 17.10 artful | Not affected |
| 16.04 LTS xenial | Not affected |
| 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

---

### [tyhicks](https://launchpad.net/~tyhicks)

mozjs contains a copy of the SpiderMonkey JavaScript engine

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.1 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.1 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12368)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-12368)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-12368)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-12368)

### Other references

* <https://www.mozilla.org/en-US/security/advisories/mfsa2018-15/#CVE-2018-12368>
* <https://www.mozilla.org/en-US/security/advisories/mfsa2018-17/#CVE-2018-12368>
* <https://www.cve.org/CVERecord?id=CVE-2018-12368>