---
title: "CVE-2017-5373\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-2017-5373?format=md
keywords: index, follow
---

# CVE-2017-5373

Publication date 25 January 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-2017-5373?format=md#impact-score)

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## Description

Memory safety bugs were reported in Firefox 50.1 and Firefox ESR 45.6. Some
of these bugs showed evidence of memory corruption and we presume that with
enough effort that some of these could be exploited to run arbitrary code.
This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and
Firefox < 51.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 17.04 zesty | Fixed 52.0.1+build2-0ubuntu1 |
| 16.10 yakkety | Fixed 51.0.1+build2-0ubuntu0.16.10.1 |
| 16.04 LTS xenial | Fixed 51.0.1+build2-0ubuntu0.16.04.1 |
| 14.04 LTS trusty | Fixed 51.0.1+build2-0ubuntu0.14.04.1 |
| 12.04 LTS precise | Fixed 51.0.1+build2-0ubuntu0.12.04.1 |
| thunderbird | 17.04 zesty | Fixed 1:45.7.0+build1-0ubuntu1 |
| 16.10 yakkety | Fixed 1:45.7.0+build1-0ubuntu0.16.10.1 |
| 16.04 LTS xenial | Fixed 1:45.7.0+build1-0ubuntu0.16.04.1 |
| 14.04 LTS trusty | Fixed 1:45.7.0+build1-0ubuntu0.14.04.1 |
| 12.04 LTS precise | Fixed 1:45.7.0+build1-0ubuntu0.12.04.1 |

---

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

## 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-2017-5373)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-5373)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-5373)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-5373)

### Related Ubuntu Security Notices (USN)

+ [USN-3175-1](https://usn.ubuntu.com/USN-3175-1)
+ Firefox vulnerabilities
+ 27 January 2017

+ [USN-3165-1](https://usn.ubuntu.com/USN-3165-1)
+ Thunderbird vulnerabilities
+ 28 January 2017

### Other references

* <https://www.mozilla.org/en-US/security/advisories/mfsa2017-01/#CVE-2017-5373>
* <https://www.mozilla.org/en-US/security/advisories/mfsa2017-03/#CVE-2017-5373>
* <https://www.cve.org/CVERecord?id=CVE-2017-5373>