# CVE-2020-12401: Firefox ESR and 1 other: During ECDSA signature generation, padding applied in the nonce designed to ensure constant-time scalar… CVE-2020-12401 is fixed in 16 products on 2 platforms, first by libnss3 2:3.35-2ubuntu2.11, released August 4, 2020. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2020-12401 - Priority: Routine - CVSS: 4.7 (Moderate) - EPSS: 0.0033 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 4, 2020 - Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2020-12401 ## Description During ECDSA signature generation, padding applied in the nonce designed to ensure constant-time scalar multiplication was removed, resulting in variable-time execution dependent on secret data. This vulnerability affects Firefox < 80 and Firefox for Android < 80. ## 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 | | Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 80.0+build2-0ubuntu0.18.04.1 | [firefox 80.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-80.0-build2-0ubuntu0.18.04.1.md) | Aug 25, 2020 | | Linux | firefox Ubuntu 20.04 LTS (focal) | 80.0+build2-0ubuntu0.20.04.1 | [firefox 80.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-80.0-build2-0ubuntu0.20.04.1.md) | Aug 25, 2020 | | Linux | firefox-geckodriver Ubuntu 18.04.6 LTS (bionic) | 80.0+build2-0ubuntu0.18.04.1 | [firefox-geckodriver 80.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-geckodriver-80.0-build2-0ubuntu0.18.04.1.md) | Aug 25, 2020 | | Linux | firefox-geckodriver Ubuntu 20.04 LTS (focal) | 80.0+build2-0ubuntu0.20.04.1 | [firefox-geckodriver 80.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-geckodriver-80.0-build2-0ubuntu0.20.04.1.md) | Aug 25, 2020 | | Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 80.0+build2-0ubuntu0.18.04.1 | [firefox-mozsymbols 80.0+build2-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-80.0-build2-0ubuntu0.18.04.1.md) | Aug 25, 2020 | | Linux | firefox-mozsymbols Ubuntu 20.04 LTS (focal) | 80.0+build2-0ubuntu0.20.04.1 | [firefox-mozsymbols 80.0+build2-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-mozsymbols-80.0-build2-0ubuntu0.20.04.1.md) | Aug 25, 2020 | | Linux | libnss3 Ubuntu 18.04.6 LTS (bionic) | 2:3.35-2ubuntu2.11 | [libnss3 2:3.35-2ubuntu2.11](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss3-2-3.35-2ubuntu2.11.md) | Aug 4, 2020 | | Linux | libnss3 Ubuntu 20.04 LTS (focal) | 2:3.49.1-1ubuntu1.4 | [libnss3 2:3.49.1-1ubuntu1.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libnss3-2-3.49.1-1ubuntu1.4.md) | Aug 4, 2020 | | Linux | libnss3-tools Ubuntu 18.04.6 LTS (bionic) | 2:3.35-2ubuntu2.11 | [libnss3-tools 2:3.35-2ubuntu2.11](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss3-tools-2-3.35-2ubuntu2.11.md) | Aug 4, 2020 | | Linux | libnss3-tools Ubuntu 20.04 LTS (focal) | 2:3.49.1-1ubuntu1.4 | [libnss3-tools 2:3.49.1-1ubuntu1.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libnss3-tools-2-3.49.1-1ubuntu1.4.md) | Aug 4, 2020 | | Linux | nss RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-devel RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-softokn RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-softokn-devel RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-softokn-freebl RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-softokn-freebl-devel RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-sysinit RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-tools RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-util RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | | Linux | nss-util-devel RHEL 8 | 0:3.53.1-17.el8_3 | [RHSA-2021:0538](https://patchblox.com/security/data/fix/linux/rhsa-2021-0538.md) | Feb 16, 2021 | --- Data as of 2026-11-08T00:53:09Z UTC. 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