CVE-2011-3062 in Firefox
Summary
by MITRE
Off-by-one error in the OpenType Sanitizer in Google Chrome before 18.0.1025.142 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted OpenType file.
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Analysis
by VulDB Data Team • 10/21/2024
The vulnerability identified as CVE-2011-3062 represents a critical off-by-one error within Google Chrome's OpenType Sanitizer component, which is responsible for processing font files to prevent potential security exploits. This flaw existed in Chrome versions prior to 18.0.1025.142 and specifically targeted the handling of OpenType font files that are commonly used in web content and document rendering. The OpenType Sanitizer is a crucial security mechanism that validates font data to prevent malicious code execution or system compromise during font processing operations.
The technical nature of this vulnerability stems from improper bounds checking within the font sanitization logic, where an off-by-one error occurs during the parsing of font table structures. This type of error typically manifests when a program incorrectly handles array indices or memory boundaries, leading to memory corruption or unexpected behavior. In this case, the flaw allows attackers to craft malicious OpenType font files that, when processed by Chrome's sanitizer, trigger buffer overflow conditions or memory access violations. The vulnerability is classified under CWE-129 as an "Improper Validation of Array Index" and represents a classic example of how seemingly benign file processing operations can become attack vectors when proper input validation is absent.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as indicated by the description suggesting "unspecified other impact." Attackers can leverage this flaw to potentially execute arbitrary code within the browser context or cause system instability through carefully crafted font files. When Chrome encounters a malicious OpenType file, the off-by-one error in the sanitizer can lead to memory corruption that may be exploited to redirect execution flow or corrupt critical system resources. This vulnerability particularly affects web browsing environments where users may unknowingly encounter malicious font files embedded in web pages, emails, or downloaded documents, making it a significant threat vector for social engineering attacks.
Mitigation strategies for CVE-2011-3062 primarily focus on immediate patching of affected Chrome versions, with users urged to upgrade to Chrome 18.0.1025.142 or later. Organizations should implement comprehensive browser update policies and consider deploying automated patch management systems to ensure all systems receive security updates promptly. Network-level defenses such as web application firewalls and content filtering systems can provide additional protection by blocking suspicious font file downloads or implementing strict file type validation. Security teams should also monitor for exploitation attempts through network traffic analysis and implement intrusion detection systems that can identify patterns associated with font-based attacks. The vulnerability demonstrates the importance of proper input validation in security-critical components and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript and VBScript" in contexts where font processing triggers code execution. Organizations should also consider implementing sandboxing techniques that isolate font processing operations from core browser functionality to limit potential impact if such vulnerabilities are exploited.