CVE-2024-7523 in Firefox
Summary
by MITRE • 08/06/2024
A select option could partially obscure security prompts. This could be used by a malicious site to trick a user into granting permissions. *This issue only affects Android versions of Firefox.* This vulnerability affects Firefox < 129.
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Analysis
by VulDB Data Team • 03/15/2025
This vulnerability in Firefox for Android represents a sophisticated user interface deception attack that exploits the browser's handling of select elements to manipulate security prompts. The flaw specifically targets the rendering behavior of HTML select options which can partially obscure security warnings and permission requests displayed by the browser. This creates a dangerous scenario where legitimate security notifications become visually obscured or partially hidden, potentially leading users to make uninformed decisions about granting permissions. The vulnerability affects only Android versions of Firefox and specifically impacts versions prior to 129, indicating a targeted issue within the mobile browser's implementation. The security implications extend beyond simple visual obscuration as they create an attack surface where malicious actors can leverage the browser's UI rendering to conduct social engineering attacks. This type of vulnerability falls under the category of user interface deception attacks that manipulate the user's perception of security warnings, potentially leading to unauthorized permission grants or other security compromises. The issue demonstrates how seemingly minor UI rendering behaviors can create significant security risks when they interact with security-critical elements.
The technical flaw stems from Firefox's implementation of HTML select element rendering on Android platforms where the select dropdown options can overlap or partially obscure security prompts that are displayed in the browser interface. This occurs due to improper z-index handling or layering of UI elements where the select element's rendering context does not properly account for security prompts that should remain fully visible and accessible to users. The vulnerability allows an attacker to position malicious select elements in such a way that they visually interfere with security notifications, making it difficult for users to properly read or respond to important permission requests. This behavior creates an attack vector where the malicious site can deliberately craft the UI to hide critical security warnings, effectively bypassing the user's ability to make informed security decisions. The flaw demonstrates a failure in the browser's UI composition model to properly manage the visual hierarchy of security-critical elements versus regular UI components, creating a situation where user attention can be manipulated through subtle UI manipulation techniques.
The operational impact of this vulnerability is significant for mobile browser security, particularly in environments where users may be less vigilant about security warnings due to the mobile interface design. When security prompts are partially obscured, users may inadvertently click through permission requests without fully understanding what they are granting access to, potentially leading to data exposure or other security compromises. The vulnerability is particularly concerning because it relies on legitimate browser functionality rather than exploiting a deeper security flaw, making it more difficult to detect and prevent. Attackers can leverage this vulnerability to conduct phishing attacks, social engineering campaigns, or other malicious activities where they need users to grant permissions without proper awareness of the implications. The issue also represents a regression in security design where the browser's UI rendering has become less protective of critical security elements, potentially affecting a large user base that relies on Firefox for Android for their browsing needs. This vulnerability can be exploited across various permission types including location access, camera access, microphone access, and other sensitive capabilities that users might grant without proper understanding of the consequences.
Mitigation strategies for this vulnerability should focus on both immediate browser updates and defensive UI design practices. Users should immediately upgrade to Firefox version 129 or later where this vulnerability has been addressed through improved UI element rendering and z-index management. Browser vendors should implement stricter UI composition rules that ensure security prompts and warnings maintain proper visual priority over regular UI elements like select dropdowns. The fix likely involves implementing proper layering mechanisms that prevent select elements from overlapping security prompts or ensuring that any such overlap is handled gracefully through visual indicators or automatic repositioning. Security researchers and developers should also consider implementing automated UI testing that specifically checks for element overlap scenarios involving security warnings. This vulnerability highlights the importance of considering security implications during UI design phases and emphasizes the need for comprehensive testing of UI interactions that could potentially compromise user security awareness. Organizations should also implement user education programs that emphasize the importance of carefully reading all security warnings, regardless of how they appear on screen. The fix for this vulnerability aligns with security best practices outlined in the CWE taxonomy for user interface security issues, specifically addressing CWE-691 where insufficient protection of security-critical UI elements leads to potential user deception. This vulnerability also maps to ATT&CK technique T1566 which involves social engineering through UI manipulation, demonstrating how seemingly benign browser functionality can be weaponized for malicious purposes.