CVE-2012-3984 in Firefox
Summary
by MITRE
Mozilla Firefox before 16.0, Thunderbird before 16.0, and SeaMonkey before 2.13 do not properly handle navigation away from a web page that has a SELECT element s menu active, which allows remote attackers to spoof page content via vectors involving absolute positioning and scrolling.
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Analysis
by VulDB Data Team • 04/18/2021
This vulnerability exists in Mozilla Firefox versions prior to 16.0, Thunderbird versions prior to 16.0, and SeaMonkey versions prior to 2.13 where the applications fail to properly manage the state of SELECT elements when users navigate away from pages containing active dropdown menus. The flaw specifically occurs when a user interacts with a SELECT element that has its dropdown menu open and then navigates to a different page or frame. This improper handling creates a window where the browser does not correctly reset or clear the active menu state, leading to potential security implications.
The technical mechanism behind this vulnerability involves the browser's handling of DOM elements and their visual states during navigation events. When a SELECT element's menu is active, the browser maintains certain visual and state properties that should be reset upon navigation. However, in affected versions, these properties persist in a way that allows attackers to manipulate the display through absolute positioning and scrolling techniques. The vulnerability is categorized under CWE-124 as "Buffer Underflow" and relates to improper handling of element states during page transitions, which can lead to memory corruption or state manipulation issues.
The operational impact of this vulnerability is significant for users who may encounter malicious websites designed to exploit this behavior. Attackers can craft web pages that, when loaded, present a SELECT element with an active menu, then navigate the user to another page while maintaining the menu state. Through careful manipulation of absolute positioning and scrolling, attackers can make it appear as though content from the original page is still visible or that malicious content is overlaid on legitimate pages. This creates opportunities for phishing attacks, content spoofing, and user confusion that can lead to credential theft or other malicious activities.
This vulnerability aligns with several ATT&CK techniques including T1531 for "Account Access Removal" and T1071.001 for "Application Layer Protocol: Web Protocols" as it exploits web application behavior to manipulate user interface elements. The attack vector specifically involves manipulation of web page navigation and element state management, making it particularly dangerous in contexts where users trust the browser's visual presentation. The vulnerability demonstrates a failure in proper state management during navigation events, which is a fundamental security principle in web browser design.
Mitigation strategies include immediate patching of affected software versions to the fixed releases of Firefox 16.0, Thunderbird 16.0, and SeaMonkey 2.13. Organizations should implement comprehensive browser update policies and ensure all users maintain current versions of these applications. Additionally, security teams should monitor for any attempts to exploit this vulnerability through web-based attacks and consider implementing browser security extensions that provide additional protection against such state manipulation techniques. The fix implemented by Mozilla involved proper handling of SELECT element states during navigation events, ensuring that active menus are correctly closed and reset when page transitions occur.