CVE-2009-0156 in Mac OS X
Summary
by MITRE
Launch Services in Apple Mac OS X 10.4.11 and 10.5 before 10.5.7 allows remote attackers to cause a denial of service (persistent Finder crash) via a crafted Mach-O executable that triggers an out-of-bounds memory read.
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Analysis
by VulDB Data Team • 05/27/2025
The vulnerability identified as CVE-2009-0156 resides within Apple Mac OS X Launch Services component, specifically affecting versions 10.4.11 and 10.5 prior to 10.5.7. This issue represents a classic out-of-bounds memory read condition that manifests through the processing of Mach-O executable files, demonstrating a fundamental flaw in how the operating system handles executable file validation and memory management during the launch process. The vulnerability operates at the intersection of system service management and executable file parsing, creating a pathway for remote exploitation that can result in persistent system instability.
The technical flaw stems from inadequate bounds checking within the Launch Services framework when processing malformed Mach-O executables. When a specially crafted Mach-O file is encountered, the system attempts to read memory locations beyond the allocated bounds of the executable structure, triggering an access violation that causes the Finder application to crash repeatedly. This memory access error occurs during the file type detection and launch preparation phase, where the system parses executable headers and metadata to determine appropriate launch behavior. The out-of-bounds read vulnerability falls under CWE-129, which specifically addresses insufficient bounds checking, and represents a critical weakness in input validation that allows attackers to manipulate memory access patterns.
The operational impact of this vulnerability extends beyond simple denial of service, creating persistent system instability that can severely disrupt user productivity and system availability. The persistent Finder crashes indicate that the vulnerability creates a condition where the system enters a loop of repeated failures, potentially requiring manual intervention to restore normal operation. This type of vulnerability can be particularly dangerous in enterprise environments where system stability is paramount, as it can lead to cascading failures affecting multiple users and applications. The remote exploitation capability means that attackers can trigger these crashes without physical access to the system, making the vulnerability particularly concerning for networked environments.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1499.004 which involves network denial of service attacks, and represents a system-level attack vector that can be leveraged to disrupt normal computing operations. The vulnerability demonstrates how seemingly minor flaws in core system components can create significant security implications, particularly when they affect fundamental services like the Finder that users rely on for daily operations. Security practitioners should consider this vulnerability as part of broader system hardening efforts, recognizing that such memory safety issues often indicate deeper architectural concerns that may manifest in other forms within the same codebase.
Mitigation strategies should focus on immediate patch deployment for affected versions, implementing additional input validation measures, and monitoring for suspicious executable file patterns that may indicate exploitation attempts. System administrators should also consider implementing application sandboxing controls and network-based intrusion detection systems to identify and block malicious executable files before they can be processed by the vulnerable Launch Services component. The vulnerability underscores the importance of regular security updates and proper memory safety practices in system-level code development, particularly for critical services that handle user input and file processing operations.