CVE-2010-1831 in Mac OS X
Summary
by MITRE
Buffer overflow in Apple Type Services (ATS) in Apple Mac OS X 10.5.8 and 10.6.x before 10.6.5 allows remote attackers to execute arbitrary code via a long name of an embedded font in a document.
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Analysis
by VulDB Data Team • 09/29/2021
The vulnerability identified as CVE-2010-1831 represents a critical buffer overflow flaw within Apple Type Services, a core component of macOS operating systems. This issue affects Mac OS X versions 10.5.8 and 10.6.x prior to 10.6.5, creating a significant security risk that could be exploited by remote attackers to gain unauthorized code execution capabilities. The vulnerability specifically targets the handling of embedded fonts within documents, making it particularly dangerous in environments where users frequently open documents from untrusted sources.
Apple Type Services serves as the foundational framework for font handling and rendering in macOS, managing the display and processing of various font formats including TrueType, OpenType, and PostScript fonts. The buffer overflow occurs when ATS processes embedded font names that exceed predetermined memory boundaries, causing memory corruption that can be leveraged by malicious actors. This flaw operates at the intersection of font processing and memory management, where insufficient input validation allows attackers to craft specially formatted documents containing excessively long font names that trigger the overflow condition.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential system compromise and data breach scenarios. When a user opens a malicious document containing an oversized embedded font name, the buffer overflow can overwrite adjacent memory locations, potentially allowing attackers to inject and execute arbitrary code with the privileges of the affected application. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how font processing libraries can become attack vectors in modern operating systems. The remote exploitation capability means that attackers do not need physical access to the system, making this vulnerability particularly concerning for enterprise environments.
Attackers exploiting this vulnerability typically craft malicious documents that contain embedded fonts with intentionally oversized name fields, often using techniques such as format string manipulation or direct memory corruption methods. The attack surface is broad as this affects any application that utilizes ATS for font rendering, including word processors, PDF viewers, and web browsers that process embedded fonts. This vulnerability has been catalogued in the MITRE ATT&CK framework under the technique of 'Exploitation for Code Execution', demonstrating how seemingly benign document processing functions can become critical attack vectors. Organizations should consider implementing comprehensive patch management strategies and network segmentation to limit the potential impact of such vulnerabilities.
The remediation approach for this vulnerability requires immediate installation of Apple's security updates, specifically the Mac OS X 10.6.5 update and subsequent patches for 10.5.8 systems. System administrators should prioritize deployment of these patches across all affected systems, as the vulnerability remains exploitable in unpatched environments. Additional protective measures include implementing application sandboxing, restricting document opening from untrusted sources, and monitoring for suspicious font-related activities in system logs. The vulnerability also highlights the importance of input validation in font processing libraries and demonstrates how third-party font handling components can introduce significant security risks to operating system environments.