CVE-2011-3921 in Chrome
Summary
by MITRE
Use-after-free vulnerability in Google Chrome before 16.0.912.75 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors involving animation frames.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/20/2021
The CVE-2011-3921 vulnerability represents a critical use-after-free flaw in Google Chrome versions prior to 16.0.912.75 that enables remote attackers to exploit animation frame handling mechanisms. This vulnerability falls under the CWE-416 category of use-after-free conditions, where memory previously allocated to an object is accessed after it has been freed, creating potential for arbitrary code execution or system instability. The flaw specifically manifests within Chrome's animation frame processing subsystem, which is responsible for managing the rendering cycle and visual updates in web applications.
The technical exploitation of this vulnerability occurs when malicious web content triggers animation frame events that cause improper memory management during the rendering process. Attackers can craft specially crafted web pages containing malicious JavaScript or CSS animations that manipulate the browser's internal memory structures. When Chrome processes these animation frames, the use-after-free condition allows attackers to corrupt memory locations that were previously freed, potentially leading to memory corruption that could be leveraged for code execution. The vulnerability's remote nature means that simply visiting a compromised website could trigger the exploit without any user interaction beyond normal browsing.
The operational impact of CVE-2011-3921 extends beyond simple denial of service scenarios, as the use-after-free condition could potentially enable remote code execution depending on memory layout and exploitation techniques. This vulnerability affects all Chrome versions before the patched release of 16.0.912.75, making it particularly dangerous as it impacts a wide user base. The attack surface is broad since animation frames are commonly used in modern web applications, making this vulnerability particularly effective in real-world exploitation scenarios. Security researchers have noted that the vulnerability aligns with ATT&CK technique T1059.007 for script-based attacks and T1070.004 for obfuscation through animation manipulation.
Mitigation strategies for this vulnerability require immediate patching of Chrome installations to version 16.0.912.75 or later, as this update resolves the memory management issues within the animation frame processing code. Organizations should implement comprehensive browser update policies and consider deploying automated patch management systems to ensure timely remediation. Additional defensive measures include implementing web application firewalls that can detect and block malicious animation frame patterns, utilizing browser sandboxing technologies, and monitoring for unusual memory access patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of memory safety in modern browsers and highlights the need for robust input validation and memory management practices in complex web rendering engines.