CVE-2015-3336 in Chrome
Summary
by MITRE
Google Chrome before 42.0.2311.90 does not always ask the user before proceeding with CONTENT_SETTINGS_TYPE_FULLSCREEN and CONTENT_SETTINGS_TYPE_MOUSELOCK changes, which allows user-assisted remote attackers to cause a denial of service (UI disruption) by constructing a crafted HTML document containing JavaScript code with requestFullScreen and requestPointerLock calls, and arranging for the user to access this document with a file: URL.
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Analysis
by VulDB Data Team • 05/09/2022
The vulnerability identified as CVE-2015-3336 represents a significant security flaw in Google Chrome browsers prior to version 42.0.2311.90 that undermines user consent mechanisms for critical browser functionalities. This issue stems from Chrome's improper handling of user permissions for fullscreen and mouse lock content settings, creating a scenario where malicious actors can exploit user trust to disrupt normal browser operations without explicit user acknowledgment. The vulnerability specifically targets the CONTENT_SETTINGS_TYPE_FULLSCREEN and CONTENT_SETTINGS_TYPE_MOUSELOCK settings, which are fundamental components of browser security that control how applications can access fullscreen mode and lock mouse pointers.
The technical implementation of this vulnerability exploits the inconsistent user consent prompts that Chrome should normally present before executing fullscreen or mouse lock operations. When a malicious HTML document containing JavaScript code with requestFullScreen and requestPointerLock calls is accessed via file: URLs, the browser fails to properly validate user intent before executing these operations. This behavior violates established security principles where user consent should always be obtained for operations that can significantly alter the user interface or access system resources. The flaw particularly manifests when users access crafted documents through file: URLs, which bypass normal web security restrictions and allow for more direct manipulation of browser behavior.
The operational impact of this vulnerability extends beyond simple user inconvenience to potentially enable more sophisticated attacks within a compromised environment. Attackers can leverage this flaw to create denial of service conditions that disrupt user workflows by forcing unexpected fullscreen transitions or mouse pointer locking scenarios that prevent normal interaction with the browser interface. This disruption can be particularly problematic in environments where users rely on specific browser configurations or when the attack occurs during critical operations. The vulnerability also demonstrates a broader pattern of insufficient input validation and user consent enforcement that could potentially be extended to other content settings within the browser's security model.
From a cybersecurity perspective, this vulnerability aligns with CWE-602, which addresses client-side restrictions that can be bypassed by attackers, and represents a failure in the principle of least privilege enforcement. The attack vector specifically utilizes file: URLs, which is a technique that can be categorized under ATT&CK technique T1059.007 for command and scripting interpreter, where attackers craft malicious content that executes within the browser context. Organizations should consider this vulnerability as part of broader browser security hygiene practices, particularly in environments where users might encounter untrusted content through file sharing or internal document repositories. The remediation approach requires updating to Chrome version 42.0.2311.90 or later, where proper user consent prompts have been implemented for fullscreen and mouse lock operations. Additionally, administrators should consider implementing browser hardening policies that restrict file URL access and monitor for unusual browser behavior patterns that might indicate exploitation attempts.