CVE-2011-0179 in Mac OS X
Summary
by MITRE
CoreText in Apple Mac OS X before 10.6.7 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a document that contains a crafted embedded font.
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Analysis
by VulDB Data Team • 10/21/2021
The vulnerability identified as CVE-2011-0179 represents a critical memory corruption flaw within CoreText, Apple's text rendering framework that operates at the core of Mac OS X operating systems. This vulnerability affects versions prior to 10.6.7 and demonstrates how embedded font processing can serve as a sophisticated attack vector for remote code execution. The flaw resides in the manner CoreText handles crafted font data within documents, creating opportunities for adversaries to manipulate memory structures and potentially gain unauthorized system access. The vulnerability's classification aligns with CWE-125, which describes out-of-bounds read conditions that can lead to memory corruption and arbitrary code execution.
The technical implementation of this vulnerability exploits the font parsing mechanisms within CoreText by embedding maliciously crafted font data within documents such as pdf files or other rich text formats. When the operating system processes these documents, the CoreText framework attempts to render the embedded fonts, triggering the memory corruption that occurs during font data interpretation. The flaw specifically manifests when the framework encounters font tables or metadata that exceed expected boundaries or contain malformed structures that cause buffer overflows or heap corruption. This memory manipulation can result in application crashes or more severe consequences where attackers can inject and execute arbitrary code within the context of the affected application. The vulnerability's operational impact is particularly concerning as it can be leveraged through various document formats without requiring user interaction beyond opening the malicious file, making it a prime candidate for drive-by attack scenarios.
The operational implications of CVE-2011-0179 extend beyond simple denial of service conditions to encompass full system compromise capabilities. Attackers can craft documents that appear legitimate to users while containing hidden malicious font data designed to exploit the CoreText vulnerability. This attack vector operates at the system level rather than requiring user privilege escalation, making it particularly dangerous in enterprise environments where users may open documents from untrusted sources. The vulnerability can be exploited across multiple applications that rely on CoreText for text rendering, including web browsers, email clients, and document processing applications. According to ATT&CK framework categorization, this vulnerability maps to T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, as the initial compromise can lead to broader system access. The vulnerability's persistence across different document formats and applications makes it a significant concern for security professionals managing Mac OS X environments, particularly those that frequently process external documents or have high user interaction with potentially malicious content.
Mitigation strategies for CVE-2011-0179 primarily focus on immediate system updates and patch management to address the underlying CoreText implementation flaws. Apple's release of Mac OS X 10.6.7 included critical fixes that resolved the memory corruption issues within the font processing pipeline, making timely patch deployment essential for system security. Organizations should implement comprehensive patch management procedures that prioritize security updates, particularly those addressing core framework vulnerabilities like CoreText. Additional protective measures include implementing sandboxing controls for applications that process external documents, configuring email and web filtering solutions to scan for potentially malicious embedded fonts, and establishing user education programs that emphasize the risks of opening untrusted documents. Network-level protections such as intrusion detection systems can help identify exploitation attempts, while endpoint protection solutions can provide additional layers of defense against font-based attacks. Security monitoring should specifically track application crashes and memory corruption events that may indicate exploitation attempts, and system administrators should maintain detailed logs of document processing activities for forensic analysis purposes. The vulnerability's resolution through Apple's security update demonstrates the importance of maintaining current operating system versions and following established security practices for vulnerability remediation.