# CVE-2017-7843: firefox: When Private Browsing mode is used, it is possible for a web worker to write persistent data to IndexedDB and fingerp...

CVE-2017-7843 is fixed in 4 products on 1 platform, first by firefox 57.0.1+build2-0ubuntu1, released June 11, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2017-7843
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0289
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 11, 2018

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 57.0.1+build2-0ubuntu1 | [firefox 57.0.1+build2-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-57.0.1-build2-0ubuntu1.md) | Jun 11, 2018 |
| Linux | firefox-globalmenu Ubuntu 18.04.6 LTS (bionic) | 57.0.1+build2-0ubuntu1 | [firefox-globalmenu 57.0.1+build2-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-globalmenu-57.0.1-build2-0ubuntu1.md) | Jun 11, 2018 |
| Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 57.0.1+build2-0ubuntu1 | [firefox-mozsymbols 57.0.1+build2-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-57.0.1-build2-0ubuntu1.md) | Jun 11, 2018 |
| Linux | firefox-testsuite Ubuntu 18.04.6 LTS (bionic) | 57.0.1+build2-0ubuntu1 | [firefox-testsuite 57.0.1+build2-0ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-testsuite-57.0.1-build2-0ubuntu1.md) | Jun 11, 2018 |

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Data as of 2026-11-07T12:40:37Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo