CVE-2011-2835 in Chrome
Summary
by MITRE
Race condition in Google Chrome before 14.0.835.163 allows attackers to cause a denial of service or possibly have unspecified other impact via vectors related to the certificate cache.
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Analysis
by VulDB Data Team • 11/20/2021
The vulnerability identified as CVE-2011-2835 represents a critical race condition flaw within Google Chrome browser versions prior to 14.0.835.163. This issue resides in the certificate cache mechanism that Chrome employs to store and manage SSL/TLS certificates during secure web browsing sessions. The race condition occurs when multiple threads or processes attempt to access and modify the certificate cache simultaneously, creating a temporal window where the cache state becomes inconsistent or corrupted. This fundamental flaw in Chrome's certificate handling system exposes the browser to potential exploitation by malicious actors who can manipulate the timing of certificate operations to trigger the vulnerable code path. The vulnerability's classification as a race condition aligns with CWE-362, which specifically addresses concurrent execution using improper synchronization. Attackers can leverage this weakness to disrupt normal browser operations through denial of service attacks, where legitimate web browsing becomes impossible due to certificate cache corruption, or potentially achieve more severe impacts including arbitrary code execution or privilege escalation depending on the specific exploitation vector.
The technical implementation of this vulnerability stems from improper synchronization mechanisms within Chrome's certificate cache management system. When the browser processes multiple certificate-related operations concurrently, such as certificate validation, caching, and retrieval, the lack of adequate locking mechanisms allows for interleaved execution that can result in corrupted cache entries. This race condition manifests when one thread attempts to modify a certificate entry while another thread is reading or processing the same entry, leading to inconsistent data states that can cause the browser to crash or behave unpredictably. The certificate cache serves as a performance optimization mechanism that stores previously validated certificates to avoid repeated validation overhead, but this optimization becomes a security liability when the underlying data structures are not properly protected against concurrent access. The vulnerability specifically impacts the certificate validation process, which is fundamental to establishing secure HTTPS connections and maintaining user trust in web communications. The timing aspect of this race condition makes it particularly challenging to detect and reproduce, as it depends on precise thread scheduling and execution timing that can vary between different system configurations and load conditions.
The operational impact of CVE-2011-2835 extends beyond simple denial of service scenarios to potentially compromise the integrity of secure web communications. When exploited successfully, this vulnerability can cause Chrome to crash or freeze during certificate processing, effectively preventing users from accessing secure websites and rendering the browser unusable for secure browsing activities. The potential for unspecified other impacts suggests that sophisticated attackers might be able to leverage this race condition to execute arbitrary code within the browser context or bypass security controls that rely on proper certificate validation. This type of vulnerability directly impacts the browser's ability to maintain secure connections, which is fundamental to the internet's security infrastructure. Organizations relying on Chrome for secure web browsing operations face significant risk, as this vulnerability could be exploited in targeted attacks against specific users or systems. The vulnerability's impact is particularly concerning in enterprise environments where secure web communications are critical for business operations, and where a single compromised browser instance could potentially lead to broader security breaches through man-in-the-middle attacks or credential theft.
Mitigation strategies for CVE-2011-2835 focus primarily on immediate browser updates and system hardening measures. The most effective remediation approach involves upgrading to Google Chrome version 14.0.835.163 or later, which includes proper synchronization mechanisms and race condition fixes in the certificate cache implementation. Organizations should implement automated patch management systems to ensure all Chrome installations are updated promptly, as this vulnerability affects a wide range of users and systems. Additional mitigations include implementing network-level security controls such as web application firewalls that can detect and block suspicious certificate-related traffic patterns, and establishing monitoring systems to detect browser crashes or unusual certificate processing behavior. Security teams should also consider implementing browser hardening measures such as disabling unnecessary certificate cache features or configuring stricter certificate validation policies. The vulnerability's exploitation requires specific timing conditions and access to the target system, but given Chrome's widespread use, the attack surface remains significant. Organizations should also prepare incident response plans that account for browser-based vulnerabilities, including procedures for isolating affected systems, monitoring for exploitation attempts, and implementing alternative secure browsing methods while patches are deployed. This vulnerability demonstrates the importance of proper concurrent programming practices and the need for thorough security testing of performance optimization features that may introduce race conditions.