CVE-2009-2826 in Mac OS X
Summary
by MITRE
Multiple integer overflows in CoreGraphics in Apple Mac OS X 10.5.8 allow remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted PDF document that triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 06/02/2025
The vulnerability described in CVE-2009-2826 represents a critical security flaw within Apple's CoreGraphics framework affecting Mac OS X 10.5.8 systems. This issue stems from improper handling of integer values during PDF processing operations, creating conditions where maliciously crafted PDF documents can trigger exploitable memory corruption scenarios. The vulnerability specifically targets the heap-based buffer overflow mechanisms within the graphics rendering subsystem, which processes graphical elements contained in PDF files. When a malicious PDF document is opened or processed by applications utilizing CoreGraphics, the integer overflow conditions cause the system to allocate insufficient memory buffers, leading to memory corruption that can be leveraged for arbitrary code execution or system instability.
The technical implementation of this vulnerability involves the manipulation of integer arithmetic operations within the PDF parsing and rendering pipeline of CoreGraphics. When processing certain PDF elements such as font descriptions, image data, or graphical transformations, the system performs calculations that can result in integer overflows when dealing with large or malformed numerical values. These overflows occur in contexts where the system calculates buffer sizes or memory allocation requirements based on user-supplied data from the PDF document. The flaw manifests as a heap-based buffer overflow because the system allocates memory on the heap using calculated sizes that exceed the intended bounds due to the integer overflow, resulting in memory corruption that can be exploited to overwrite critical program data or control flow information.
From an operational perspective, this vulnerability presents significant risk to Mac OS X users who may encounter malicious PDF documents through email attachments, web downloads, or file sharing networks. The remote execution capability means that attackers can potentially compromise systems without requiring local access or user interaction beyond opening a malicious document. The impact extends beyond simple application crashes to full system compromise, as successful exploitation can lead to arbitrary code execution with the privileges of the affected application process. This vulnerability affects not only the PDF viewer applications but also any software that relies on CoreGraphics for rendering graphical content, including web browsers, document processing applications, and various productivity tools that handle PDF files.
The mitigation strategies for this vulnerability involve multiple layers of protection and system hardening measures. Apple addressed this issue through security updates that included bounds checking and proper integer overflow handling within the CoreGraphics framework. System administrators should ensure that all Mac OS X systems are updated to the latest security patches, particularly those addressing the integer overflow conditions in PDF processing. Additional protective measures include implementing sandboxing policies for PDF handling applications, configuring network-based security controls to filter potentially malicious PDF content, and deploying application whitelisting solutions that restrict execution of untrusted PDF processing software. Organizations should also consider implementing security awareness training to reduce the risk of users inadvertently opening malicious PDF documents that could exploit this vulnerability.
This vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions that can lead to buffer overflows and memory corruption, and demonstrates characteristics consistent with ATT&CK technique T1203, which involves the exploitation of memory corruption vulnerabilities for privilege escalation and code execution. The vulnerability represents a classic example of how graphics processing libraries can become attack vectors when they fail to properly validate input data, particularly in environments where users frequently process untrusted document formats. The remediation approach emphasizes the importance of robust input validation and memory safety practices in system libraries, particularly those handling complex data formats like PDF documents that contain rich graphical content and require extensive memory management operations.