# CVE-2021-23968: Firefox ESR and 2 others: If Content Security Policy blocked frame navigation, the full destination of a redirect served in the…

CVE-2021-23968 is fixed in 11 products on 2 platforms, first by RHSA-2021:0655, released February 24, 2021. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2021-23968
- Priority: Urgent
- CVSS: 4.3 (Critical)
- EPSS: 0.0131
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 24, 2021
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2021-23968

## Description

If Content Security Policy blocked frame navigation, the full destination of a redirect served in the frame was reported in the violation report; as opposed to the original frame URI. This could be used to leak sensitive information contained in such URIs. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

## 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) | 78.10.0 | [Mozilla Thunderbird (en-US) 78.10.0](https://patchblox.com/security/data/fix/windows-app/mozilla.thunderbird-78.10.0.md) | Apr 15, 2021 |
| Linux | firefox RHEL 8 | 0:78.8.0-1.el8_3 | [RHSA-2021:0655](https://patchblox.com/security/data/fix/linux/rhsa-2021-0655.md) | Feb 24, 2021 |
| Linux | firefox Ubuntu 18.04.6 LTS (bionic) | 86.0+build3-0ubuntu0.18.04.1 | [firefox 86.0+build3-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-86.0-build3-0ubuntu0.18.04.1.md) | Feb 26, 2021 |
| Linux | firefox Ubuntu 20.04 LTS (focal) | 86.0+build3-0ubuntu0.20.04.1 | [firefox 86.0+build3-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-86.0-build3-0ubuntu0.20.04.1.md) | Feb 26, 2021 |
| Linux | firefox ol 8 | 0:78.8.0-1.0.1.el8_3 | [ELSA-2021-0655](https://patchblox.com/security/data/fix/linux/elsa-2021-0655.md) | Feb 26, 2021 |
| Linux | firefox-geckodriver Ubuntu 18.04.6 LTS (bionic) | 86.0+build3-0ubuntu0.18.04.1 | [firefox-geckodriver 86.0+build3-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-geckodriver-86.0-build3-0ubuntu0.18.04.1.md) | Feb 26, 2021 |
| Linux | firefox-geckodriver Ubuntu 20.04 LTS (focal) | 86.0+build3-0ubuntu0.20.04.1 | [firefox-geckodriver 86.0+build3-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-geckodriver-86.0-build3-0ubuntu0.20.04.1.md) | Feb 26, 2021 |
| Linux | firefox-mozsymbols Ubuntu 18.04.6 LTS (bionic) | 86.0+build3-0ubuntu0.18.04.1 | [firefox-mozsymbols 86.0+build3-0ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-firefox-mozsymbols-86.0-build3-0ubuntu0.18.04.1.md) | Feb 26, 2021 |
| Linux | firefox-mozsymbols Ubuntu 20.04 LTS (focal) | 86.0+build3-0ubuntu0.20.04.1 | [firefox-mozsymbols 86.0+build3-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-firefox-mozsymbols-86.0-build3-0ubuntu0.20.04.1.md) | Feb 26, 2021 |
| Linux | thunderbird RHEL 8 | 0:78.8.0-1.el8_3 | [RHSA-2021:0657](https://patchblox.com/security/data/fix/linux/rhsa-2021-0657.md) | Feb 24, 2021 |
| 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) | 1:78.8.1+build1-0ubuntu0.20.04.1 | [thunderbird 1:78.8.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-thunderbird-1-78.8.1-build1-0ubuntu0.20.04.1.md) | Apr 22, 2021 |
| Linux | thunderbird ol 8 | 0:78.8.0-1.0.1.el8_3 | [ELSA-2021-0657](https://patchblox.com/security/data/fix/linux/elsa-2021-0657.md) | Feb 26, 2021 |
| 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) | 1:78.8.1+build1-0ubuntu0.20.04.1 | [thunderbird-gnome-support 1:78.8.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-thunderbird-gnome-support-1-78.8.1-build1-0ubuntu0.20.04.1.md) | Apr 22, 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) | 1:78.8.1+build1-0ubuntu0.20.04.1 | [thunderbird-mozsymbols 1:78.8.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-thunderbird-mozsymbols-1-78.8.1-build1-0ubuntu0.20.04.1.md) | Apr 22, 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) | 1:78.8.1+build1-0ubuntu0.20.04.1 | [xul-ext-calendar-timezones 1:78.8.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xul-ext-calendar-timezones-1-78.8.1-build1-0ubuntu0.20.04.1.md) | Apr 22, 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) | 1:78.8.1+build1-0ubuntu0.20.04.1 | [xul-ext-gdata-provider 1:78.8.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xul-ext-gdata-provider-1-78.8.1-build1-0ubuntu0.20.04.1.md) | Apr 22, 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) | 1:78.8.1+build1-0ubuntu0.20.04.1 | [xul-ext-lightning 1:78.8.1+build1-0ubuntu0.20.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-xul-ext-lightning-1-78.8.1-build1-0ubuntu0.20.04.1.md) | Apr 22, 2021 |

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