CVE-2009-2827 in Mac OS X
Summary
by MITRE
Heap-based buffer overflow in Disk Images in Apple Mac OS X 10.5.8 allows user-assisted remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted FAT filesystem on a disk image.
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Analysis
by VulDB Data Team • 06/02/2025
The vulnerability identified as CVE-2009-2827 represents a critical heap-based buffer overflow within Apple Mac OS X 10.5.8's Disk Images component that specifically targets the handling of FAT filesystems within disk images. This flaw exists in the kernel-level subsystem responsible for processing disk image files, making it particularly dangerous as it can be exploited through user-assisted remote attack vectors. The vulnerability stems from inadequate bounds checking when parsing FAT filesystem structures within disk image containers, allowing maliciously crafted filesystem data to overwrite adjacent memory locations in the heap allocation space.
The technical implementation of this vulnerability involves the improper handling of buffer boundaries during FAT filesystem parsing operations within the Disk Images framework. When a maliciously crafted disk image containing a specially constructed FAT filesystem is opened, the system's memory management routines fail to validate the size and structure of filesystem metadata before copying data into heap-allocated buffers. This oversight creates a condition where attacker-controlled data can overflow the intended buffer boundaries, potentially overwriting critical heap metadata or adjacent memory regions containing program execution control structures. The vulnerability specifically affects the way the system processes FAT filesystem structures, particularly when dealing with extended boot sectors or cluster chain information that exceeds expected buffer dimensions.
From an operational perspective, this vulnerability presents a significant risk to Mac OS X 10.5.8 systems as it enables both remote code execution and denial of service attacks through user-assisted exploitation scenarios. Attackers can craft disk images with malicious FAT filesystem structures that, when opened by unsuspecting users, trigger the buffer overflow condition. The exploit potential extends beyond simple application crashes to full system compromise, as successful exploitation can lead to arbitrary code execution with the privileges of the affected process. The remote aspect of the attack means that malicious actors can deliver the exploit through various channels including email attachments, web downloads, or network file shares, making it particularly dangerous in enterprise environments where users may encounter untrusted disk images.
The vulnerability maps directly to CWE-121 Heap-based Buffer Overflow, which specifically addresses buffer overflows occurring in heap memory regions where insufficient bounds checking allows data to overwrite adjacent memory locations. This classification aligns with the fundamental nature of the flaw where heap memory allocation routines fail to validate input data size before copying into allocated buffers. The attack surface is further expanded when considering the ATT&CK framework's T1059.007 technique for Command and Scripting Interpreter, as successful exploitation could enable attackers to execute arbitrary commands through the compromised system. Additionally, this vulnerability demonstrates characteristics of T1566.001 Credential Access through Social Engineering, as it relies on user-assisted exploitation where victims must open the malicious disk image.
Mitigation strategies for CVE-2009-2827 should prioritize immediate system updates to Apple's security patches, as the vulnerability was addressed through subsequent macOS updates that implemented proper bounds checking for FAT filesystem parsing. Organizations should implement strict disk image handling policies that prevent automatic mounting of untrusted disk images and establish robust sandboxing mechanisms for disk image processing. Network administrators should consider implementing content filtering solutions that can detect and block potentially malicious disk image files. System administrators should also configure automatic security updates to ensure timely patch deployment and consider implementing endpoint protection solutions that can monitor for suspicious disk image processing activities. The remediation process should include comprehensive system hardening measures that restrict user privileges during disk image operations and establish proper input validation mechanisms for all filesystem parsing operations.