Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
CVE-2020-6820 is fixed in 10 products on 2 platforms, first by firefox 74.0.1+build1-0ubuntu0.18.04.1, released April 2, 2020. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021. Patch Radar priority: Patch now.
Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Windows apps | |||
| Mozilla Firefox ESR (en-US) | 78.0esr | Mozilla Firefox ESR (en-US) 78.0esr | Jun 25, 2020 |
| Linux | |||
| firefox · RHEL 8 | 0:68.6.1-1.el8_1 | RHSA-2020:1341 | Apr 7, 2020 |
| firefox · Ubuntu 18.04.6 LTS (bionic) | 74.0.1+build1-0ubuntu0.18.04.1 | firefox 74.0.1+build1-0ubuntu0.18.04.1 | Apr 2, 2020 |
| firefox · Ubuntu 20.04 LTS (focal) | 75.0+build3-0ubuntu1 | firefox 75.0+build3-0ubuntu1 | Apr 6, 2020 |
| firefox · ol 8 | 0:68.6.1-1.0.1.el8_1 | ELSA-2020-1341 | Apr 9, 2020 |
| firefox-geckodriver · Ubuntu 18.04.6 LTS (bionic) | 74.0.1+build1-0ubuntu0.18.04.1 | firefox-geckodriver 74.0.1+build1-0ubuntu0.18.04.1 | Apr 2, 2020 |
| firefox-geckodriver · Ubuntu 20.04 LTS (focal) | 75.0+build3-0ubuntu1 | firefox-geckodriver 75.0+build3-0ubuntu1 | Apr 6, 2020 |
| firefox-mozsymbols · Ubuntu 18.04.6 LTS (bionic) | 74.0.1+build1-0ubuntu0.18.04.1 | firefox-mozsymbols 74.0.1+build1-0ubuntu0.18.04.1 | Apr 2, 2020 |
| firefox-mozsymbols · Ubuntu 20.04 LTS (focal) | 75.0+build3-0ubuntu1 | firefox-mozsymbols 75.0+build3-0ubuntu1 | Apr 6, 2020 |
| thunderbird · RHEL 8 | 0:68.7.0-1.el8_1 | RHSA-2020:1495 | Apr 16, 2020 |
| thunderbird · Ubuntu 18.04.6 LTS (bionic) | 1:68.7.0+build1-0ubuntu0.18.04.1 | thunderbird 1:68.7.0+build1-0ubuntu0.18.04.1 | Apr 6, 2020 |
| thunderbird · Ubuntu 20.04 LTS (focal) | 1:68.7.0+build1-0ubuntu1 | thunderbird 1:68.7.0+build1-0ubuntu1 | Apr 6, 2020 |
| thunderbird · ol 8 | 0:68.7.0-1.0.1.el8_1 | ELSA-2020-1495 | Apr 18, 2020 |
| thunderbird-gnome-support · Ubuntu 18.04.6 LTS (bionic) | 1:68.7.0+build1-0ubuntu0.18.04.1 | thunderbird-gnome-support 1:68.7.0+build1-0ubuntu0.18.04.1 | Apr 6, 2020 |
| thunderbird-gnome-support · Ubuntu 20.04 LTS (focal) | 1:68.7.0+build1-0ubuntu1 | thunderbird-gnome-support 1:68.7.0+build1-0ubuntu1 | Apr 6, 2020 |
| thunderbird-mozsymbols · Ubuntu 18.04.6 LTS (bionic) | 1:68.7.0+build1-0ubuntu0.18.04.1 | thunderbird-mozsymbols 1:68.7.0+build1-0ubuntu0.18.04.1 | Apr 6, 2020 |
| thunderbird-mozsymbols · Ubuntu 20.04 LTS (focal) | 1:68.7.0+build1-0ubuntu1 | thunderbird-mozsymbols 1:68.7.0+build1-0ubuntu1 | Apr 6, 2020 |
| xul-ext-calendar-timezones · Ubuntu 18.04.6 LTS (bionic) | 1:68.7.0+build1-0ubuntu0.18.04.1 | xul-ext-calendar-timezones 1:68.7.0+build1-0ubuntu0.18.04.1 | Apr 6, 2020 |
| xul-ext-calendar-timezones · Ubuntu 20.04 LTS (focal) | 1:68.7.0+build1-0ubuntu1 | xul-ext-calendar-timezones 1:68.7.0+build1-0ubuntu1 | Apr 6, 2020 |
| xul-ext-gdata-provider · Ubuntu 18.04.6 LTS (bionic) | 1:68.7.0+build1-0ubuntu0.18.04.1 | xul-ext-gdata-provider 1:68.7.0+build1-0ubuntu0.18.04.1 | Apr 6, 2020 |
| xul-ext-gdata-provider · Ubuntu 20.04 LTS (focal) | 1:68.7.0+build1-0ubuntu1 | xul-ext-gdata-provider 1:68.7.0+build1-0ubuntu1 | Apr 6, 2020 |
| xul-ext-lightning · Ubuntu 18.04.6 LTS (bionic) | 1:68.7.0+build1-0ubuntu0.18.04.1 | xul-ext-lightning 1:68.7.0+build1-0ubuntu0.18.04.1 | Apr 6, 2020 |
| xul-ext-lightning · Ubuntu 20.04 LTS (focal) | 1:68.7.0+build1-0ubuntu1 | xul-ext-lightning 1:68.7.0+build1-0ubuntu1 | Apr 6, 2020 |
Patch Radar data is free to use with attribution. Terms and how to credit it.
Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.