CVE-2011-1809 in Chrome
Summary
by MITRE
Use-after-free vulnerability in the accessibility feature in Google Chrome before 12.0.742.91 allows remote attackers to cause a denial of service or possibly have unspecified other impact via unknown vectors.
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Analysis
by VulDB Data Team • 11/08/2021
The vulnerability identified as CVE-2011-1809 represents a critical use-after-free flaw within Google Chrome's accessibility feature implementation. This type of vulnerability occurs when a program continues to reference memory that has already been freed, creating potential exploitation opportunities for malicious actors. The issue specifically affects Chrome versions prior to 12.0.742.91, indicating a window of exposure where users were particularly vulnerable to attack vectors targeting this memory management weakness. The accessibility features in web browsers typically provide enhanced functionality for users with disabilities, including screen readers and keyboard navigation systems that interact with web content at a deep level.
The technical nature of this use-after-free vulnerability stems from improper memory management within Chrome's accessibility subsystem, where memory allocation and deallocation processes fail to maintain proper synchronization. When the accessibility feature handles certain web content or user interactions, it may prematurely free memory resources while still maintaining references to them. This creates a scenario where subsequent operations attempt to access already-released memory locations, potentially leading to unpredictable behavior. The unspecified other impacts mentioned in the CVE description suggest that exploitation could extend beyond simple denial of service to include more severe consequences such as arbitrary code execution or privilege escalation. This aligns with the common characteristics of use-after-free vulnerabilities, which are classified under CWE-416 as "Use After Free" and are frequently exploited in the ATT&CK framework under techniques related to memory corruption and privilege escalation.
The operational impact of this vulnerability extends significantly beyond simple service disruption, as remote attackers can leverage the flaw to execute arbitrary code on affected systems. When an attacker successfully exploits this vulnerability, they can potentially gain control over the browser process and subsequently the underlying operating system, especially when the browser runs with elevated privileges. The accessibility feature in question likely processes web content in ways that make it particularly susceptible to memory corruption, as these features often need to maintain persistent state information about web elements. The potential for unspecified other impacts indicates that this vulnerability could serve as a stepping stone for more sophisticated attacks, including those targeting the broader system through browser-based exploits. Organizations using affected Chrome versions face significant risk, as the vulnerability can be exploited through standard web browsing activities without requiring user interaction beyond visiting malicious websites.
Mitigation strategies for CVE-2011-1809 primarily focus on immediate software updates and patch management protocols. The most effective remediation involves upgrading to Chrome version 12.0.742.91 or later, which includes memory management fixes specifically addressing the use-after-free condition. System administrators should implement robust patch management processes to ensure rapid deployment of security updates across all affected systems. Additional protective measures include browser hardening techniques such as disabling unnecessary accessibility features when not required, implementing sandboxing mechanisms, and deploying web application firewalls to monitor and filter potentially malicious traffic. The vulnerability also underscores the importance of keeping all browser components updated, as accessibility features often require complex integration with underlying system resources. Security monitoring should include detection of unusual memory access patterns and potential exploitation attempts targeting memory corruption vulnerabilities, with particular attention to browser-based attacks that leverage accessibility features as attack vectors. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts.