---
title: "CVE-2019-11745\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-2019-11745?format=md
keywords: index, follow
---

# CVE-2019-11745

Publication date 25 November 2019

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-2019-11745?format=md#impact-score)

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## Description

When encrypting with a block cipher, if a call to NSC\_EncryptUpdate was
made with data smaller than the block size, a small out of bounds write
could occur. This could have caused heap corruption and a potentially
exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox
ESR < 68.3, and Firefox < 71.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 19.10 eoan | Fixed 71.0+build5-0ubuntu0.19.10.1 |
| 19.04 disco | Fixed 71.0+build5-0ubuntu0.19.04.1 |
| 18.04 LTS bionic | Fixed 71.0+build5-0ubuntu0.18.04.1 |
| 16.04 LTS xenial | Fixed 71.0+build5-0ubuntu0.16.04.1 |
| 14.04 LTS trusty | Not in release |
| nss | 19.10 eoan | Fixed 2:3.45-1ubuntu2.1 |
| 19.04 disco | Fixed 2:3.42-1ubuntu2.3 |
| 18.04 LTS bionic | Fixed 2:3.35-2ubuntu2.5 |
| 16.04 LTS xenial | Fixed 2:3.28.4-0ubuntu0.16.04.8 |
| 14.04 LTS trusty | Fixed 2:3.28.4-0ubuntu0.14.04.5+esm2  Ubuntu Pro |
| thunderbird | 19.10 eoan | Fixed 1:68.4.1+build1-0ubuntu0.19.10.1 |
| 19.04 disco | Ignored end of life |
| 18.04 LTS bionic | Fixed 1:68.4.1+build1-0ubuntu0.18.04.1 |
| 16.04 LTS xenial | Fixed 1:68.7.0+build1-0ubuntu0.16.04.2 |
| 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)
* [Patch details](https://ubuntu.com/security/CVE-2019-11745?format=md#patch-details)

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### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| nss | * Upstream:   <https://hg.mozilla.org/projects/nss/rev/1e22a0c93afe9f46545560c86caedef9dab6cfda> * Upstream:   <https://hg.mozilla.org/projects/nss/rev/60bca7c6dc6dc44579b9b3e0fb62ca3b82d92eec> * Upstream:   <https://hg.mozilla.org/projects/nss/rev/4c20de402b3901df0cde590a46be2ba49adc028e> |

## 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:3.1/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-2019-11745)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-11745)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-11745)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-11745)

### Related Ubuntu Security Notices (USN)

+ [USN-4216-2](https://usn.ubuntu.com/USN-4216-2)
+ Firefox vulnerabilities
+ 13 December 2019

+ [USN-4216-1](https://usn.ubuntu.com/USN-4216-1)
+ Firefox vulnerabilities
+ 9 December 2019

+ [USN-4335-1](https://usn.ubuntu.com/USN-4335-1)
+ Thunderbird vulnerabilities
+ 21 April 2020

+ [USN-4241-1](https://usn.ubuntu.com/USN-4241-1)
+ Thunderbird vulnerabilities
+ 16 January 2020

+ [USN-4203-1](https://usn.ubuntu.com/USN-4203-1)
+ NSS vulnerability
+ 27 November 2019

+ [USN-4203-2](https://usn.ubuntu.com/USN-4203-2)
+ NSS vulnerability
+ 27 November 2019

### Other references

* <https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.44.3_release_notes>
* <https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.47.1_release_notes>
* <https://www.mozilla.org/en-US/security/advisories/mfsa2019-38/#CVE-2019-11745>
* <https://www.cve.org/CVERecord?id=CVE-2019-11745>