CVE-2011-2618 in Web Browser
Summary
by MITRE
Opera before 11.50 allows remote attackers to cause a denial of service (application crash) via web script that moves a (1) AUDIO element or (2) VIDEO element between windows.
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Analysis
by VulDB Data Team • 11/13/2021
The vulnerability identified as CVE-2011-2618 represents a denial of service flaw in Opera web browsers prior to version 11.50 that stems from improper handling of media elements during cross-window operations. This issue specifically affects AUDIO and VIDEO elements when they are moved between different browser windows or frames, creating a condition where malicious web scripts can trigger application instability. The flaw demonstrates characteristics consistent with memory corruption vulnerabilities, where the browser's handling of media element references becomes inconsistent when transitioning between window contexts.
The technical exploitation of this vulnerability occurs through JavaScript execution that manipulates media elements by moving them between different windows or frames within the browser environment. When an attacker crafts a web page containing malicious script that performs operations on AUDIO or VIDEO elements, specifically targeting their movement between windows, the browser's internal rendering and memory management systems fail to properly handle these transitions. This results in memory corruption or invalid pointer references that ultimately lead to application crashes. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-248, which covers exposure of uninitialized variables, as the improper handling of element references creates conditions where memory locations become inaccessible or corrupted.
Operationally, this vulnerability presents a significant risk to users of older Opera versions as it can be exploited through standard web browsing activities without requiring any special privileges or user interaction beyond visiting a malicious website. The denial of service impact means that legitimate browser functionality is disrupted, forcing users to restart their browsers and potentially lose unsaved work or session data. Attackers can leverage this vulnerability in phishing campaigns or drive-by download scenarios where simply visiting a compromised website can cause the browser to crash, effectively preventing normal web browsing operations. The vulnerability also demonstrates characteristics that align with ATT&CK technique T1499.004, which covers network denial of service attacks, as the exploitation causes service disruption through application-level crashes rather than network-level interference.
Mitigation strategies for CVE-2011-2618 primarily involve upgrading to Opera version 11.50 or later, where the underlying memory handling and media element management has been corrected. System administrators should prioritize patch management to ensure all Opera installations are updated to versions that address this vulnerability. Additional protective measures include implementing browser security policies that restrict cross-window scripting operations, deploying web application firewalls that can detect and block malicious script patterns, and educating users about the risks of visiting untrusted websites. Organizations should also consider implementing sandboxing techniques for browser operations and monitoring for unusual application crash patterns that might indicate exploitation attempts. The vulnerability serves as a reminder of the importance of proper memory management in web browser implementations and the critical need for regular security updates to protect against known exploitation vectors.