CVE-2024-31392 in Firefox
Summary
by MITRE • 04/03/2024
If an insecure element was added to a page after a delay, Firefox would not replace the secure icon with a mixed content security status This vulnerability affects Firefox for iOS < 124.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 04/09/2025
This vulnerability represents a critical security flaw in Firefox for iOS versions prior to 124 where the browser fails to properly update its security indicators when insecure content is dynamically loaded onto a secure webpage. The issue stems from the browser's handling of mixed content detection mechanisms, specifically when elements are added to a page after an initial delay has passed. When a webpage loads securely but subsequently incorporates insecure resources through dynamic content loading, the security status indicator should transition from a secure state to a mixed content warning. However, Firefox for iOS does not perform this transition correctly, leaving users with a false sense of security.
The technical implementation flaw involves Firefox's security status monitoring system which relies on timing-sensitive checks for mixed content detection. When elements are injected into a page after the initial page load, the browser's security subsystem fails to re-evaluate the overall security status of the page. This creates a window where users may interact with content that contains both secure and insecure elements without being properly warned about the mixed content status. The vulnerability is particularly concerning because it affects mobile users who may be less likely to notice subtle security indicators or may trust the browser's security status indicators.
From an operational impact perspective, this vulnerability exposes users to man-in-the-middle attacks and potential data interception scenarios. Attackers could exploit this by injecting insecure content into secure pages, potentially leading to credential theft, session hijacking, or data exfiltration. The mixed content warning system is a fundamental security feature designed to alert users to potential security risks, and its failure undermines the browser's security posture. This vulnerability directly impacts the principle of least privilege and user awareness, as users are not properly informed about the security status of the content they are interacting with.
The security implications align with CWE-611 (Improper Restriction of XML External Entity Reference) and CWE-310 (Cryptographic Issues) categories, as the vulnerability affects how the browser handles security boundaries and content validation. From an ATT&CK framework perspective, this vulnerability maps to T1566 (Phishing) and T1071.004 (Application Layer Protocol: DNS) where attackers could leverage the false security indicators to deceive users into interacting with malicious content. The vulnerability also relates to T1592 (Pre-Attack) and T1005 (Data from Local System) as it creates opportunities for attackers to establish persistent access through misleading security indicators. The recommended mitigation involves updating to Firefox for iOS version 124 or later where the security status handling has been corrected. Organizations should also implement additional monitoring for mixed content detection and consider user education about security indicators to reduce the risk of exploitation.