CVE-2011-3093 in Chrome
Summary
by MITRE
Google Chrome before 19.0.1084.46 does not properly handle glyphs, which allows remote attackers to cause a denial of service (out-of-bounds read) via unspecified vectors.
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Analysis
by VulDB Data Team • 03/24/2021
The vulnerability identified as CVE-2011-3093 represents a critical out-of-bounds read flaw within Google Chrome versions prior to 19.0.1084.46, specifically related to the browser's handling of font glyphs. This issue falls under the category of memory safety vulnerabilities and demonstrates how improper input validation in graphical rendering components can lead to severe security implications. The flaw occurs when Chrome processes font glyphs, which are the visual representations of characters that make up text displayed on web pages, creating a potential attack surface that adversaries can exploit for malicious purposes.
The technical implementation of this vulnerability stems from Chrome's insufficient bounds checking when processing font glyph data structures. Glyphs are complex graphical elements that contain various metadata and rendering instructions, and when these elements are improperly handled, they can trigger memory access violations that result in out-of-bounds reads. This particular vulnerability manifests as a denial of service condition where remote attackers can craft malicious web content that, when rendered by the affected browser, causes the application to read memory locations beyond the intended buffer boundaries. Such out-of-bounds reads typically do not lead to code execution but can cause the browser to crash or become unresponsive, effectively creating a denial of service scenario that impacts user experience and system availability.
From an operational impact perspective, this vulnerability presents a significant risk to users of older Chrome versions as it enables remote exploitation without requiring user interaction beyond visiting a malicious website. The attack vector is particularly concerning because it leverages the browser's core rendering capabilities, which are invoked frequently during normal web browsing activities. This makes the vulnerability highly exploitable in real-world scenarios where users may inadvertently encounter malicious content. The vulnerability's classification aligns with CWE-129, which addresses improper validation of length of input buffers, and can be mapped to ATT&CK technique T1203, which covers the use of web-based attacks to cause denial of service conditions.
The remediation for this vulnerability requires immediate upgrade to Google Chrome version 19.0.1084.46 or later, which includes proper bounds checking mechanisms for glyph processing. Security administrators should implement comprehensive patch management protocols to ensure all affected systems receive updates promptly. Organizations should also consider deploying web application firewalls and content filtering solutions to mitigate the risk of exploitation while waiting for patches to be deployed. Additionally, browser hardening techniques such as sandboxing and privilege separation should be maintained to limit the potential impact of any successful exploitation attempts. The vulnerability serves as a reminder of the importance of regular security updates and the critical role that proper input validation plays in preventing memory safety issues that can compromise system stability and availability.