---
title: "CVE-2016-2821\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-2016-2821?format=md
keywords: index, follow
---

# CVE-2016-2821

Publication date 8 June 2016

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2016-2821?format=md#impact-score)

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## Description

Use-after-free vulnerability in the mozilla::dom::Element class in Mozilla
Firefox before 47.0 and Firefox ESR 45.x before 45.2, when contenteditable
mode is enabled, allows remote attackers to execute arbitrary code or cause
a denial of service (heap memory corruption) by triggering deletion of DOM
elements that were created in the editor.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 16.04 LTS xenial | Fixed 47.0+build3-0ubuntu0.16.04.1 |
| 15.10 wily | Fixed 47.0+build3-0ubuntu0.15.10.1 |
| 14.04 LTS trusty | Fixed 47.0+build3-0ubuntu0.14.04.1 |
| 12.04 LTS precise | Fixed 47.0+build3-0ubuntu0.12.04.1 |
| thunderbird | 16.04 LTS xenial | Not affected |
| 15.10 wily | Not affected |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Not affected |

---

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

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-2821)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-2821)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-2821)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-2821)

### Related Ubuntu Security Notices (USN)

+ [USN-2993-1](https://usn.ubuntu.com/USN-2993-1)
+ Firefox vulnerabilities
+ 9 June 2016

### Other references

* <https://www.mozilla.org/en-US/security/advisories/mfsa2016-51/>
* <https://www.cve.org/CVERecord?id=CVE-2016-2821>