# CVE-2020-15683: Firefox ESR and 2 others: Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox…

CVE-2020-15683 is fixed in 11 products on 2 platforms, first by Mozilla Thunderbird (en-US) 78.4.0, released October 19, 2020. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2020-15683
- Priority: High
- CVSS: 9.8 (Important)
- EPSS: 0.0267
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 21, 2020
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2020-15683

## Description

Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox ESR 78.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.4, Firefox < 82, and Thunderbird < 78.4.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | Mozilla Firefox ESR (en-US) | 91.0 | [Mozilla Firefox ESR (en-US) 91.0](https://patchblox.com/security/data/fix/windows-app/mozilla.firefox.esr-91.0.md) | Aug 4, 2021 |
| Windows apps | Mozilla Thunderbird (en-US) | 78.4.0 | [Mozilla Thunderbird (en-US) 78.4.0](https://patchblox.com/security/data/fix/windows-app/mozilla.thunderbird-78.4.0.md) | Oct 19, 2020 |
| Linux | firefox RHEL 8 | 0:78.4.0-1.el8_2 | [RHSA-2020:4317](https://patchblox.com/security/data/fix/linux/rhsa-2020-4317.md) | Oct 22, 2020 |
| Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 82.0+build2-0ubuntu0.18.04.1 | [firefox 82.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-82.0-build2-0ubuntu0.18.04.1.md) | Oct 21, 2020 |
| Linux | firefox Ubuntu 20.04 LTS (focal) | 82.0+build2-0ubuntu0.20.04.1 | [firefox 82.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-82.0-build2-0ubuntu0.20.04.1.md) | Oct 21, 2020 |
| Linux | firefox ol 8 | 0:78.4.0-1.0.1.el8_2 | [ELSA-2020-4317](https://patchblox.com/security/data/fix/linux/elsa-2020-4317.md) | Oct 26, 2020 |
| Linux | firefox-geckodriver Ubuntu 18.04.6 LTS (bionic) | 82.0+build2-0ubuntu0.18.04.1 | [firefox-geckodriver 82.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-geckodriver-82.0-build2-0ubuntu0.18.04.1.md) | Oct 21, 2020 |
| Linux | firefox-geckodriver Ubuntu 20.04 LTS (focal) | 82.0+build2-0ubuntu0.20.04.1 | [firefox-geckodriver 82.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-geckodriver-82.0-build2-0ubuntu0.20.04.1.md) | Oct 21, 2020 |
| Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 82.0+build2-0ubuntu0.18.04.1 | [firefox-mozsymbols 82.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-82.0-build2-0ubuntu0.18.04.1.md) | Oct 21, 2020 |
| Linux | firefox-mozsymbols Ubuntu 20.04 LTS (focal) | 82.0+build2-0ubuntu0.20.04.1 | [firefox-mozsymbols 82.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-mozsymbols-82.0-build2-0ubuntu0.20.04.1.md) | Oct 21, 2020 |
| Linux | thunderbird RHEL 8 | 0:78.4.0-1.el8_3 | [RHSA-2020:4913](https://patchblox.com/security/data/fix/linux/rhsa-2020-4913.md) | Nov 4, 2020 |
| Linux | thunderbird Ubuntu 18.04.6 LTS (bionic) | 1:78.8.1+build1-0ubuntu0.18.04.1 | [thunderbird 1:78.8.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-1-78.8.1-build1-0ubuntu0.18.04.1.md) | Apr 22, 2021 |
| Linux | thunderbird Ubuntu 20.04 LTS (focal) | 1:78.7.1+build1-0ubuntu0.20.04.1 | [thunderbird 1:78.7.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-thunderbird-1-78.7.1-build1-0ubuntu0.20.04.1.md) | Jan 25, 2021 |
| Linux | thunderbird ol 8 | 0:78.4.0-1.0.1.el8_3 | [ELSA-2020-4913](https://patchblox.com/security/data/fix/linux/elsa-2020-4913.md) | Nov 17, 2020 |
| Linux | thunderbird-gnome-support Ubuntu 18.04.6 LTS (bionic) | 1:78.8.1+build1-0ubuntu0.18.04.1 | [thunderbird-gnome-support 1:78.8.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-gnome-support-1-78.8.1-build1-0ubuntu0.18.04.1.md) | Apr 22, 2021 |
| Linux | thunderbird-gnome-support Ubuntu 20.04 LTS (focal) | 1:78.7.1+build1-0ubuntu0.20.04.1 | [thunderbird-gnome-support 1:78.7.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-thunderbird-gnome-support-1-78.7.1-build1-0ubuntu0.20.04.1.md) | Jan 25, 2021 |
| Linux | thunderbird-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 1:78.8.1+build1-0ubuntu0.18.04.1 | [thunderbird-mozsymbols 1:78.8.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-thunderbird-mozsymbols-1-78.8.1-build1-0ubuntu0.18.04.1.md) | Apr 22, 2021 |
| Linux | thunderbird-mozsymbols Ubuntu 20.04 LTS (focal) | 1:78.7.1+build1-0ubuntu0.20.04.1 | [thunderbird-mozsymbols 1:78.7.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-thunderbird-mozsymbols-1-78.7.1-build1-0ubuntu0.20.04.1.md) | Jan 25, 2021 |
| Linux | xul-ext-calendar-timezones Ubuntu 18.04.6 LTS (bionic) | 1:78.8.1+build1-0ubuntu0.18.04.1 | [xul-ext-calendar-timezones 1:78.8.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-xul-ext-calendar-timezones-1-78.8.1-build1-0ubuntu0.18.04.1.md) | Apr 22, 2021 |
| Linux | xul-ext-calendar-timezones Ubuntu 20.04 LTS (focal) | 1:78.7.1+build1-0ubuntu0.20.04.1 | [xul-ext-calendar-timezones 1:78.7.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xul-ext-calendar-timezones-1-78.7.1-build1-0ubuntu0.20.04.1.md) | Jan 25, 2021 |
| Linux | xul-ext-gdata-provider Ubuntu 18.04.6 LTS (bionic) | 1:78.8.1+build1-0ubuntu0.18.04.1 | [xul-ext-gdata-provider 1:78.8.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-xul-ext-gdata-provider-1-78.8.1-build1-0ubuntu0.18.04.1.md) | Apr 22, 2021 |
| Linux | xul-ext-gdata-provider Ubuntu 20.04 LTS (focal) | 1:78.7.1+build1-0ubuntu0.20.04.1 | [xul-ext-gdata-provider 1:78.7.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xul-ext-gdata-provider-1-78.7.1-build1-0ubuntu0.20.04.1.md) | Jan 25, 2021 |
| Linux | xul-ext-lightning Ubuntu 18.04.6 LTS (bionic) | 1:78.8.1+build1-0ubuntu0.18.04.1 | [xul-ext-lightning 1:78.8.1+build1-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-xul-ext-lightning-1-78.8.1-build1-0ubuntu0.18.04.1.md) | Apr 22, 2021 |
| Linux | xul-ext-lightning Ubuntu 20.04 LTS (focal) | 1:78.7.1+build1-0ubuntu0.20.04.1 | [xul-ext-lightning 1:78.7.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xul-ext-lightning-1-78.7.1-build1-0ubuntu0.20.04.1.md) | Jan 25, 2021 |

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