---
title: "CVE-2017-7801\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-2017-7801?format=md
keywords: index, follow
---

# CVE-2017-7801

Publication date 10 August 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**9.8 · Critical**

[Score breakdown](https://ubuntu.com/security/CVE-2017-7801?format=md#impact-score)

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## Description

A use-after-free vulnerability can occur while re-computing layout for a
"marquee" element during window resizing where the updated style object is
freed while still in use. This results in a potentially exploitable crash.
This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and
Firefox < 55.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2017-7801?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 19.04 disco | Fixed 55.0.2+build1-0ubuntu4 |
| 18.10 cosmic | Fixed 55.0.2+build1-0ubuntu4 |
| 18.04 LTS bionic | Fixed 55.0.2+build1-0ubuntu4 |
| 17.10 artful | Fixed 55.0.2+build1-0ubuntu4 |
| 17.04 zesty | Fixed 55.0.1+build2-0ubuntu0.17.04.2 |
| 16.04 LTS xenial | Fixed 55.0.1+build2-0ubuntu0.16.04.2 |
| 14.04 LTS trusty | Fixed 55.0.1+build2-0ubuntu0.14.04.2 |
| mozjs38 | 19.04 disco | Not in release |
| 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not affected |
| 17.10 artful | Ignored end of life |
| 17.04 zesty | Ignored end of life |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| thunderbird | 19.04 disco | Fixed 1:52.4.0+build1-0ubuntu2 |
| 18.10 cosmic | Fixed 1:52.4.0+build1-0ubuntu2 |
| 18.04 LTS bionic | Fixed 1:52.4.0+build1-0ubuntu2 |
| 17.10 artful | Fixed 1:52.4.0+build1-0ubuntu2 |
| 17.04 zesty | Fixed 1:52.3.0+build1-0ubuntu0.17.04.1 |
| 16.04 LTS xenial | Fixed 1:52.3.0+build1-0ubuntu0.16.04.1 |
| 14.04 LTS trusty | Fixed 1:52.3.0+build1-0ubuntu0.14.04.1 |

---

* [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)

mozjs38 contains a copy of the SpiderMonkey JavaScript engine

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

9.8 · Critical

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 9.8 · Critical |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7801)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-7801)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-7801)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-7801)

### Related Ubuntu Security Notices (USN)

+ [USN-3391-1](https://usn.ubuntu.com/USN-3391-1)
+ Firefox vulnerabilities
+ 15 August 2017

+ [USN-3416-1](https://usn.ubuntu.com/USN-3416-1)
+ Thunderbird vulnerabilities
+ 14 September 2017

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2017-7801>