Description
Sandboxed iframes on webpages could potentially allow downloads to the device, bypassing the expected sandbox restrictions declared on the parent page. This vulnerability was fixed in Firefox for iOS 141.
Published: 2025-08-19
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: Unauthorized local file downloads bypassing sandbox restrictions
Action: Immediate Patch
AI Analysis

Impact

Sandboxed iframes on webpages can trigger a file download on the device even when the parent page declares sandbox restrictions. This flaw allows a user to receive a download intended to be blocked by the sandbox, representing an improper verification or authorization weakness (CWE-693). The impact is the unauthorized acquisition of data on the device without user consent.

Affected Systems

Mozilla Firefox for iOS is affected. Versions before 141 contain the flaw, while version 141 and later incorporate the fix that prevents the sandboxed iframe download bypass.

Risk and Exploitability

The CVSS score of 9.8 classifies this vulnerability as critical. The EPSS score of less than 1% indicates a low probability of observed exploitation at this time. The flaw is not listed in the CISA KEV catalog. Based on the description, it is inferred that an attacker could embed a sandboxed iframe in a malicious or compromised website presented to a user on an iOS device, causing the browser to initiate a download that bypasses the intended sandbox limits.

Generated by OpenCVE AI on April 20, 2026 at 19:51 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update Firefox for iOS to version 141 or later to apply the vendor’s fix.
  • If an immediate update is not possible, avoid browsing sites that use sandboxed iframes for downloading content, or use a different browser that correctly enforces sandbox restrictions.
  • Configure the device to require explicit user confirmation for file downloads, and disable automatic download of unknown file types.

Generated by OpenCVE AI on April 20, 2026 at 19:51 UTC.

Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2025-25230 Sandboxed iframes on webpages could potentially allow downloads to the device, bypassing the expected sandbox restrictions declared on the parent page This vulnerability affects Firefox for iOS < 141.
History

Mon, 13 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
Description Sandboxed iframes on webpages could potentially allow downloads to the device, bypassing the expected sandbox restrictions declared on the parent page This vulnerability affects Firefox for iOS < 141. Sandboxed iframes on webpages could potentially allow downloads to the device, bypassing the expected sandbox restrictions declared on the parent page. This vulnerability was fixed in Firefox for iOS 141.
Title Sandboxed iframes could allow local downloads despite sandbox restrictions

Thu, 21 Aug 2025 18:45:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla firefox
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:*:iphone_os:*:*
Vendors & Products Mozilla firefox

Thu, 21 Aug 2025 12:45:00 +0000

Type Values Removed Values Added
First Time appeared Apple
Apple ios
Mozilla
Mozilla firefox For Ios
Vendors & Products Apple
Apple ios
Mozilla
Mozilla firefox For Ios

Wed, 20 Aug 2025 16:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-693
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Tue, 19 Aug 2025 21:00:00 +0000

Type Values Removed Values Added
Description Sandboxed iframes on webpages could potentially allow downloads to the device, bypassing the expected sandbox restrictions declared on the parent page This vulnerability affects Firefox for iOS < 141.
References

Subscriptions

Apple Ios
Mozilla Firefox Firefox For Ios
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-04-13T14:30:52.883Z

Reserved: 2025-07-17T02:35:52.284Z

Link: CVE-2025-54143

cve-icon Vulnrichment

Updated: 2025-08-20T14:03:00.609Z

cve-icon NVD

Status : Modified

Published: 2025-08-19T21:15:27.557

Modified: 2026-04-13T15:17:01.840

Link: CVE-2025-54143

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-20T20:00:10Z

Weaknesses