---
title: "CVE-2016-5258\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-2016-5258?format=md
keywords: index, follow
---

# CVE-2016-5258

Publication date 3 August 2016

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-2016-5258?format=md#impact-score)

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## Description

Use-after-free vulnerability in the WebRTC socket thread in Mozilla Firefox
before 48.0 and Firefox ESR 45.x before 45.3 allows remote attackers to
execute arbitrary code by leveraging incorrect free operations on DTLS
objects during the shutdown of a WebRTC session.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 16.04 LTS xenial | Fixed 48.0+build2-0ubuntu0.16.04.1 |
| 14.04 LTS trusty | Fixed 48.0+build2-0ubuntu0.14.04.1 |
| 12.04 LTS precise | Fixed 48.0+build2-0ubuntu0.12.04.1 |
| thunderbird | 16.04 LTS xenial | 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**

8.8 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | Required |
  | 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:N/UI:R/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-5258)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-5258)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-5258)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-5258)

### Related Ubuntu Security Notices (USN)

+ [USN-3044-1](https://usn.ubuntu.com/USN-3044-1)
+ Firefox vulnerabilities
+ 5 August 2016

### Other references

* <https://www.mozilla.org/en-US/security/advisories/mfsa2016-72/>
* <https://bugzilla.mozilla.org/show_bug.cgi?id=1279146>
* <https://www.cve.org/CVERecord?id=CVE-2016-5258>