Sandboxed Iframe Download Bypass in Firefox for iOS
CVE-2025-54143

9.8CRITICAL

Key Information:

Vendor

Mozilla
Status
Firefox For iOS
Vendor
CVE Published:
19 August 2025

What is CVE-2025-54143?

A vulnerability exists in Firefox for iOS where sandboxed iframes fail to enforce proper restrictions, permitting unauthorized file downloads to the device. This flaw compromises user security by allowing actions that should be contained within the confines of the sandboxed environment, leading to potential data exposure. The affected versions are those prior to 141, emphasizing the importance of users updating their applications to mitigate this risk.

Affected Version(s)

Firefox for iOS < 141

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1912671
https://www.mozilla.org/security/advisories/mfsa2025-60/

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Narendra Bhati
.
CVE-2025-54143 : Sandboxed Iframe Download Bypass in Firefox for iOS