# CVE-2020-15682: Firefox ESR and 1 other: When a link to an external protocol was clicked, a prompt was presented that allowed the user to choose…

CVE-2020-15682 is fixed in 4 products on 2 platforms, first by firefox 82.0+build2-0ubuntu0.18.04.1, released October 21, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2020-15682
- Priority: Routine
- CVSS: 6.5 (Low)
- EPSS: 0.0048
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 21, 2020
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2020-15682

## Description

When a link to an external protocol was clicked, a prompt was presented that allowed the user to choose what application to open it in. An attacker could induce that prompt to be associated with an origin they didn't control, resulting in a spoofing attack. This was fixed by changing external protocol prompts to be tab-modal while also ensuring they could not be incorrectly associated with a different origin. This vulnerability affects Firefox < 82.

## 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) | 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-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 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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