CVE-2010-2663 in Web Browser
Summary
by MITRE
Opera before 10.60 allows remote attackers to cause a denial of service (application hang) via an ended event handler that changes the SRC attribute of an AUDIO element.
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Analysis
by VulDB Data Team • 09/20/2021
The vulnerability described in CVE-2010-2663 represents a significant denial of service flaw affecting Opera web browsers prior to version 10.60. This issue specifically targets the browser's handling of audio elements within web pages, creating a condition where maliciously crafted web content can cause the application to become unresponsive or hang entirely. The flaw operates through a sophisticated interaction between JavaScript event handling and HTML media element manipulation, demonstrating the complex nature of modern web browser security vulnerabilities.
The technical mechanism behind this vulnerability involves an ended event handler that modifies the source attribute of an AUDIO element. When an audio element reaches the end of its playback, the browser triggers an ended event that can be intercepted and modified by JavaScript code. In vulnerable versions of Opera, when this event handler attempts to change the src attribute of the audio element, it creates a recursive or infinite loop condition that causes the browser application to hang. This behavior stems from improper state management within the browser's media handling subsystem, where the change to the src attribute triggers a new event processing cycle that cannot be properly resolved. The vulnerability is classified under CWE-400, which deals with unspecified denial of service conditions, and specifically relates to improper handling of event sequences in multimedia components.
The operational impact of this vulnerability extends beyond simple application hang, as it provides attackers with a reliable method to disrupt user browsing sessions and potentially affect system availability. An attacker could craft malicious web pages that, when loaded in Opera browsers, would cause the application to become unresponsive, forcing users to manually terminate the browser process or restart their systems. This type of denial of service attack can be particularly effective in environments where users rely heavily on browser-based applications or where automated browser sessions are common. The vulnerability affects the core user experience and can be exploited in various contexts including malicious websites, phishing campaigns, or targeted attacks against specific user groups, making it a serious concern for both individual users and enterprise security teams.
Mitigation strategies for this vulnerability require immediate browser updates to version 10.60 or later, which contain the necessary patches to properly handle audio element event sequences and prevent the recursive state changes that cause the hang condition. Security administrators should also implement web content filtering measures to block access to known malicious sites that may exploit this vulnerability. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping their browsers updated. From a broader security perspective, this vulnerability highlights the need for comprehensive event handling validation in multimedia components and demonstrates the importance of proper state management in browser rendering engines. The remediation process should also include monitoring for similar patterns in other media elements and ensuring that all event handlers properly validate their inputs and prevent infinite recursion conditions. Organizations should consider implementing browser hardening measures and regular security assessments to identify and address similar vulnerabilities in their browser environments.