CVE-2011-2849 in Chrome
Summary
by MITRE
The WebSockets implementation in Google Chrome before 14.0.835.163 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via unspecified vectors.
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Analysis
by VulDB Data Team • 11/20/2021
The vulnerability identified as CVE-2011-2849 represents a critical denial of service flaw within Google Chrome's WebSocket implementation that existed prior to version 14.0.835.163. This issue stems from improper handling of WebSocket connections that can be exploited by remote attackers to crash the browser application through NULL pointer dereference conditions. The vulnerability specifically affects the WebSocket protocol implementation which is used for full-duplex communication channels between web browsers and servers, enabling real-time data exchange. WebSocket connections are fundamental to modern web applications and are commonly used in chat applications, live updates, and collaborative tools, making this vulnerability particularly concerning from a security perspective.
The technical flaw manifests as a NULL pointer dereference during WebSocket processing, where the browser's JavaScript engine or underlying WebSocket library fails to properly validate incoming connection parameters or data streams. When maliciously crafted WebSocket frames or connection requests are sent to a vulnerable Chrome instance, the application attempts to access a null memory reference, leading to an immediate crash of the browser process. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference conditions, representing a common class of software defects that can result in application instability and potential information disclosure. The vulnerability's impact extends beyond simple service disruption as it can be leveraged in more sophisticated attacks where repeated exploitation can lead to persistent denial of service conditions.
From an operational standpoint, this vulnerability presents significant risk to users who rely on Chrome for web browsing, particularly in enterprise environments where browser stability is paramount. Attackers can exploit this vulnerability through various means including malicious websites, compromised web applications, or through man-in-the-middle attacks that intercept WebSocket communications. The vulnerability's remote nature means that users do not need to perform any specific actions to be affected, as simply visiting a compromised website that attempts to establish a WebSocket connection can trigger the exploit. This makes the vulnerability particularly dangerous in scenarios where users browse untrusted content or where web applications are not properly secured against WebSocket-based attacks.
The exploitation of this vulnerability aligns with ATT&CK technique T1499 which covers network denial of service attacks, and specifically demonstrates how application-level flaws can be leveraged to achieve system-level disruption. Organizations should prioritize immediate patching of affected Chrome versions, as the vulnerability can be exploited without user interaction and provides attackers with a straightforward method to compromise browser stability. Security teams should also implement network monitoring to detect unusual WebSocket traffic patterns that may indicate exploitation attempts, while browser administrators should consider implementing additional security measures such as WebSocket traffic filtering and monitoring for anomalous connection behaviors. The vulnerability serves as a reminder of the importance of thorough input validation in network protocol implementations and the need for robust error handling in web browser components that process external data streams.