CVE-2014-1256 in Mac OS X
Summary
by MITRE
Buffer overflow in Apple Type Services (ATS) in Apple OS X before 10.9.2 allows attackers to bypass the App Sandbox protection mechanism via crafted Mach messages.
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Analysis
by VulDB Data Team • 04/12/2025
The vulnerability identified as CVE-2014-1256 represents a critical buffer overflow flaw within Apple Type Services, a core component of Apple's operating system that manages font rendering and text processing. This vulnerability specifically affects Apple OS X versions prior to 10.9.2, creating a significant security risk that extends beyond typical application-level flaws. The flaw resides in how ATS handles Mach messages, which are the fundamental communication mechanism used by the macOS kernel for inter-process communication and system-level operations.
The technical exploitation of this vulnerability occurs through crafted Mach messages that trigger a buffer overflow condition within the Apple Type Services framework. When the system processes these maliciously constructed messages, the overflow allows attackers to overwrite adjacent memory regions, potentially enabling arbitrary code execution. The vulnerability is particularly dangerous because it operates at a system level rather than within individual applications, making it a prime target for bypassing the App Sandbox protection mechanism that is designed to contain application privileges and prevent unauthorized system access. This bypass capability fundamentally undermines the security model that Apple implemented to isolate applications from each other and from core system resources.
The operational impact of CVE-2014-1256 extends far beyond simple privilege escalation, as it allows attackers to circumvent the sandboxing protections that are critical for maintaining system integrity and user security. By exploiting this vulnerability, an attacker could potentially gain elevated privileges and execute malicious code with system-level access, effectively neutralizing the security boundaries that Apple's sandboxing implementation was designed to enforce. The attack vector through Mach messages makes this vulnerability particularly insidious because it can be triggered through legitimate system communication channels, making detection and prevention more challenging. This flaw directly relates to CWE-121, which describes buffer overflow conditions that occur when insufficient bounds checking is performed on buffers, and can be mapped to ATT&CK technique T1055 for process injection and T1068 for local privilege escalation.
The remediation for this vulnerability required Apple to implement proper bounds checking in the Mach message handling code within Apple Type Services, ensuring that incoming messages are properly validated before processing. System administrators and users should immediately apply the security updates released by Apple as part of OS X 10.9.2, which include patches that address the buffer overflow condition and restore proper sandboxing protections. Organizations should also implement monitoring for unusual Mach message activity and ensure that all systems are updated to the latest supported versions of macOS to prevent exploitation of this and related vulnerabilities. The patch demonstrates the importance of maintaining proper input validation and memory management practices in system-level components that handle inter-process communication, as these components form the foundation of operating system security and are often targeted by sophisticated attackers seeking to establish persistent access to systems.