CVE-2009-0155 in Mac OS X
Summary
by MITRE
Integer underflow in CoreGraphics in Apple Mac OS X 10.5 before 10.5.7, iPhone OS 1.0 through 2.2.1, and iPhone OS for iPod touch 1.1 through 2.2.1 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted PDF file that triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 09/04/2019
The vulnerability described in CVE-2009-0155 represents a critical integer underflow flaw within Apple's CoreGraphics framework affecting multiple operating systems including Mac OS X 10.5 before 10.5.7 and various versions of iPhone OS. This vulnerability stems from improper handling of integer values during memory allocation processes, creating a condition where an attacker can manipulate input data to cause arithmetic underflow. The flaw specifically manifests when processing crafted PDF files, making it particularly dangerous in environments where PDF rendering is common. The integer underflow occurs during heap memory allocation calculations, where the result of subtracting two integers becomes smaller than the minimum value that can be represented, leading to unexpected behavior in memory management.
The technical execution of this vulnerability involves a heap-based buffer overflow scenario that can be triggered through carefully constructed PDF documents. When CoreGraphics processes these malicious files, the integer underflow causes the system to allocate insufficient memory for buffer operations, subsequently leading to memory corruption. This memory corruption can be exploited to overwrite adjacent memory locations, potentially allowing attackers to execute arbitrary code with the privileges of the affected application. The vulnerability affects the rendering pipeline of PDF documents within Apple's operating systems, making it particularly concerning given the widespread use of PDF files in both personal and enterprise environments. The flaw operates at the kernel level within CoreGraphics, which means that successful exploitation could result in complete system compromise.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass full system compromise and arbitrary code execution capabilities. Attackers can leverage this vulnerability to remotely execute code on targeted systems without requiring any special privileges or user interaction beyond opening a malicious PDF file. The vulnerability affects multiple Apple platforms, including desktop operating systems and mobile devices, amplifying its potential impact. Applications that rely on CoreGraphics for PDF rendering become vulnerable, including web browsers, email clients, and document viewers. The exploitability of this vulnerability is enhanced by the fact that PDF files can be delivered through various channels including email attachments, web downloads, and malicious websites, making it particularly dangerous in real-world scenarios. The vulnerability's presence in both desktop and mobile operating systems creates a significant attack surface that security professionals must address.
Mitigation strategies for CVE-2009-0155 primarily focus on immediate system updates and patches provided by Apple. Organizations should prioritize deployment of the security updates released for Mac OS X 10.5.7 and the corresponding iPhone OS versions, as these patches address the underlying integer underflow condition in CoreGraphics. Network administrators should implement content filtering measures to prevent users from accessing potentially malicious PDF files, particularly through email gateways and web proxies. The vulnerability aligns with CWE-191, which specifically addresses integer underflow conditions, and can be categorized under ATT&CK technique T1203 for exploitation of software vulnerabilities. System monitoring should include detection of unusual memory allocation patterns and buffer overflow attempts, while security teams should consider implementing sandboxing measures for PDF processing applications. Additionally, users should be educated about the risks of opening PDF files from untrusted sources, and organizations should establish secure document handling protocols. The vulnerability demonstrates the importance of proper integer overflow and underflow checking in memory management routines, highlighting the need for robust input validation and secure coding practices in system-level frameworks.