Firefox ESR and 2 others: When Responsive Design Mode was enabled, it used references to objects that were previously freed.
CVE-2021-23995 is fixed in 11 products on 2 platforms, first by Mozilla Thunderbird (en-US) 78.10.0, released April 15, 2021. It is not reported as exploited. Patch Radar priority: High.
When Responsive Design Mode was enabled, it used references to objects that were previously freed. We presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Windows apps | |||
| Mozilla Firefox ESR (en-US) | 91.0 | Mozilla Firefox ESR (en-US) 91.0 | Aug 4, 2021 |
| Mozilla Thunderbird (en-US) | 78.10.0 | Mozilla Thunderbird (en-US) 78.10.0 | Apr 15, 2021 |
| Linux | |||
| firefox · RHEL 8 | 0:78.10.0-1.el8_3 | RHSA-2021:1360 | Apr 26, 2021 |
| firefox · Ubuntu 18.04.6 LTS (bionic) | 88.0+build2-0ubuntu0.18.04.2 | firefox 88.0+build2-0ubuntu0.18.04.2 | Apr 25, 2021 |
| firefox · Ubuntu 20.04 LTS (focal) | 88.0+build2-0ubuntu0.20.04.1 | firefox 88.0+build2-0ubuntu0.20.04.1 | Apr 25, 2021 |
| firefox · ol 8 | 0:78.10.0-1.0.1.el8_3 | ELSA-2021-1360 | Apr 27, 2021 |
| firefox-geckodriver · Ubuntu 18.04.6 LTS (bionic) | 88.0+build2-0ubuntu0.18.04.2 | firefox-geckodriver 88.0+build2-0ubuntu0.18.04.2 | Apr 25, 2021 |
| firefox-geckodriver · Ubuntu 20.04 LTS (focal) | 88.0+build2-0ubuntu0.20.04.1 | firefox-geckodriver 88.0+build2-0ubuntu0.20.04.1 | Apr 25, 2021 |
| firefox-mozsymbols · Ubuntu 18.04.6 LTS (bionic) | 88.0+build2-0ubuntu0.18.04.2 | firefox-mozsymbols 88.0+build2-0ubuntu0.18.04.2 | Apr 25, 2021 |
| firefox-mozsymbols · Ubuntu 20.04 LTS (focal) | 88.0+build2-0ubuntu0.20.04.1 | firefox-mozsymbols 88.0+build2-0ubuntu0.20.04.1 | Apr 25, 2021 |
| thunderbird · RHEL 8 | 0:78.10.0-1.el8_3 | RHSA-2021:1353 | Apr 26, 2021 |
| thunderbird · Ubuntu 18.04.6 LTS (bionic) | 1:78.11.0+build1-0ubuntu0.18.04.2 | thunderbird 1:78.11.0+build1-0ubuntu0.18.04.2 | Jun 1, 2021 |
| thunderbird · Ubuntu 20.04 LTS (focal) | 1:78.11.0+build1-0ubuntu0.20.04.2 | thunderbird 1:78.11.0+build1-0ubuntu0.20.04.2 | Jun 1, 2021 |
| thunderbird · ol 8 | 0:78.10.0-1.0.1.el8_3 | ELSA-2021-1353 | Apr 27, 2021 |
| thunderbird-gnome-support · Ubuntu 18.04.6 LTS (bionic) | 1:78.11.0+build1-0ubuntu0.18.04.2 | thunderbird-gnome-support 1:78.11.0+build1-0ubuntu0.18.04.2 | Jun 1, 2021 |
| thunderbird-gnome-support · Ubuntu 20.04 LTS (focal) | 1:78.11.0+build1-0ubuntu0.20.04.2 | thunderbird-gnome-support 1:78.11.0+build1-0ubuntu0.20.04.2 | Jun 1, 2021 |
| thunderbird-mozsymbols · Ubuntu 18.04.6 LTS (bionic) | 1:78.11.0+build1-0ubuntu0.18.04.2 | thunderbird-mozsymbols 1:78.11.0+build1-0ubuntu0.18.04.2 | Jun 1, 2021 |
| thunderbird-mozsymbols · Ubuntu 20.04 LTS (focal) | 1:78.11.0+build1-0ubuntu0.20.04.2 | thunderbird-mozsymbols 1:78.11.0+build1-0ubuntu0.20.04.2 | Jun 1, 2021 |
| xul-ext-calendar-timezones · Ubuntu 18.04.6 LTS (bionic) | 1:78.11.0+build1-0ubuntu0.18.04.2 | xul-ext-calendar-timezones 1:78.11.0+build1-0ubuntu0.18.04.2 | Jun 1, 2021 |
| xul-ext-calendar-timezones · Ubuntu 20.04 LTS (focal) | 1:78.11.0+build1-0ubuntu0.20.04.2 | xul-ext-calendar-timezones 1:78.11.0+build1-0ubuntu0.20.04.2 | Jun 1, 2021 |
| xul-ext-gdata-provider · Ubuntu 18.04.6 LTS (bionic) | 1:78.11.0+build1-0ubuntu0.18.04.2 | xul-ext-gdata-provider 1:78.11.0+build1-0ubuntu0.18.04.2 | Jun 1, 2021 |
| xul-ext-gdata-provider · Ubuntu 20.04 LTS (focal) | 1:78.11.0+build1-0ubuntu0.20.04.2 | xul-ext-gdata-provider 1:78.11.0+build1-0ubuntu0.20.04.2 | Jun 1, 2021 |
| xul-ext-lightning · Ubuntu 18.04.6 LTS (bionic) | 1:78.11.0+build1-0ubuntu0.18.04.2 | xul-ext-lightning 1:78.11.0+build1-0ubuntu0.18.04.2 | Jun 1, 2021 |
| xul-ext-lightning · Ubuntu 20.04 LTS (focal) | 1:78.11.0+build1-0ubuntu0.20.04.2 | xul-ext-lightning 1:78.11.0+build1-0ubuntu0.20.04.2 | Jun 1, 2021 |
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.