CVE-2011-3958 in iOS
Summary
by MITRE
Google Chrome before 17.0.963.46 does not properly perform casts of variables during handling of a column span, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted document.
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Analysis
by VulDB Data Team • 04/13/2021
The vulnerability identified as CVE-2011-3958 represents a critical type confusion issue within Google Chrome's rendering engine that affects versions prior to 17.0.963.46. This flaw occurs during the processing of HTML table elements, specifically when handling column spans within table structures. The vulnerability stems from improper type casting operations that occur when Chrome attempts to process variables during the rendering of table cells with column spans. The issue manifests when the browser encounters malformed or crafted HTML documents containing table elements with specific column span configurations that trigger unexpected behavior in the underlying JavaScript engine.
The technical exploitation of this vulnerability exploits a type confusion scenario where Chrome's V8 JavaScript engine fails to properly validate or cast variable types during the table rendering process. When processing HTML tables with column spans, the browser's internal mechanisms attempt to perform operations on variables that are expected to be of one type but are actually of another type. This type confusion creates a condition where memory corruption can occur, leading to unpredictable behavior. The vulnerability is particularly dangerous because it can be triggered through web pages without requiring user interaction, making it a prime candidate for drive-by download attacks.
From an operational impact perspective, this vulnerability enables remote attackers to execute denial of service attacks against Chrome users by simply loading a malicious webpage containing the crafted HTML table structure. The potential for unspecified other impacts suggests that the type confusion could potentially be leveraged to execute arbitrary code on affected systems, though the primary exploitation vector remains denial of service. The vulnerability affects all users of Chrome versions prior to 17.0.963.46, making it particularly widespread given Chrome's market share and usage patterns. Security researchers have classified this vulnerability as high-risk due to its potential for remote code execution and the ease with which it can be triggered through standard web browsing activities.
This vulnerability aligns with CWE-466, which describes the improper handling of pointer type conversions or type confusion in software systems. The flaw demonstrates poor input validation and type checking within Chrome's HTML rendering pipeline, particularly in how it handles table-related DOM elements. The attack surface is expanded through the use of the ATT&CK framework's technique T1203, where adversaries leverage browser vulnerabilities to execute arbitrary code or cause system instability. Organizations should immediately update to Chrome version 17.0.963.46 or later to mitigate this risk, as the vulnerability can be exploited through standard web browsing without requiring any special privileges or user interaction. Additionally, implementing web application firewalls and content security policies can provide additional layers of protection against exploitation attempts targeting this specific vulnerability.
The root cause of this vulnerability highlights the complexity of modern browser security and the challenges of maintaining type safety in dynamic JavaScript environments. Chrome's rendering engine must handle numerous edge cases when processing HTML documents, and this particular flaw demonstrates how seemingly innocuous table processing operations can lead to critical security issues. The vulnerability also underscores the importance of proper memory management and type validation in browser engines, as similar issues have been identified in other browser vendors' implementations. Organizations should consider implementing automated patch management systems to ensure timely updates and reduce exposure windows for such vulnerabilities. The incident serves as a reminder of the critical need for continuous security testing and validation of browser components, particularly those handling complex DOM manipulation and rendering operations.