---
title: "CVE-2017-7843\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-2017-7843?format=md
keywords: index, follow
---

# CVE-2017-7843

Publication date 11 June 2018

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-2017-7843?format=md#impact-score)

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## Description

When Private Browsing mode is used, it is possible for a web worker to
write persistent data to IndexedDB and fingerprint a user uniquely.
IndexedDB should not be available in Private Browsing mode and this stored
data will persist across multiple private browsing mode sessions because it
is not cleared when exiting. This vulnerability affects Firefox ESR <
52.5.2 and Firefox < 57.0.1.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| firefox | 18.04 LTS bionic | Fixed 57.0.1+build2-0ubuntu1 |
| 17.10 artful | Fixed 57.0.1+build2-0ubuntu0.17.10.1 |
| 17.04 zesty | Fixed 57.0.1+build2-0ubuntu0.17.04.1 |
| 16.04 LTS xenial | Fixed 57.0.1+build2-0ubuntu0.16.04.1 |
| 14.04 LTS trusty | Fixed 57.0.1+build2-0ubuntu0.14.04.1 |

---

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

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

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

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

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7843)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-7843)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-7843)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-7843)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2017-7843>