CVE-2011-0983 in Chrome
Summary
by MITRE
Google Chrome before 9.0.597.94 does not properly handle anonymous blocks, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via unknown vectors that lead to a "stale pointer."
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Analysis
by VulDB Data Team • 10/17/2021
The vulnerability identified as CVE-2011-0983 affects Google Chrome versions prior to 9.0.597.94 and relates to improper handling of anonymous blocks within the browser's rendering engine. This flaw represents a classic memory management issue that can lead to severe operational consequences including denial of service conditions and potential arbitrary code execution. The vulnerability stems from how Chrome processes anonymous blocks in its document object model which can result in stale pointer references during memory operations.
The technical implementation of this vulnerability involves Chrome's handling of CSS anonymous blocks, which are generated when the browser encounters certain formatting scenarios where explicit block elements are not defined. These anonymous blocks are typically created to maintain proper layout structures in the document rendering process. When Chrome fails to properly manage the lifecycle of these anonymous blocks, it can lead to situations where pointers reference memory locations that have already been freed or reallocated. This stale pointer condition creates a memory corruption scenario that remote attackers can exploit through carefully crafted web content.
From an operational impact perspective, this vulnerability allows remote attackers to trigger denial of service conditions by causing Chrome to crash or become unresponsive. The unspecified other impacts mentioned in the description suggest that the stale pointer condition could potentially be leveraged for more sophisticated attacks including privilege escalation or arbitrary code execution. The vulnerability is particularly concerning because it can be triggered through web content without requiring user interaction, making it a significant risk for web-based attack scenarios.
The flaw aligns with CWE-476 which describes null pointer dereference conditions, and potentially CWE-121 for buffer overflow conditions that can occur due to improper memory management. From an ATT&CK framework perspective, this vulnerability maps to T1059 for command and scripting interpreter and T1499 for endpoint denial of service, as it enables attackers to disrupt browser operations and potentially execute malicious code. The vulnerability demonstrates how seemingly minor rendering engine issues can cascade into serious security concerns when memory management is not properly handled.
Mitigation strategies for this vulnerability include immediate upgrade to Chrome version 9.0.597.94 or later, which contains the necessary patches to properly handle anonymous block lifecycle management. Organizations should also implement network-level protections such as web application firewalls that can detect and block malicious content that might trigger this vulnerability. Browser hardening techniques including sandboxing and strict content security policies can provide additional defense-in-depth measures. Regular security updates and patch management processes should be enforced to ensure all browser installations remain current with security fixes. The vulnerability serves as a reminder of the importance of proper memory management in browser engines and the critical need for comprehensive testing of rendering components against potential exploitation vectors.