CVE-2016-1826 in Mac OS X
Summary
by MITRE
Integer overflow in the dtrace implementation in the kernel in Apple OS X before 10.11.5 allows attackers to execute arbitrary code in a privileged context via a crafted app.
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Analysis
by VulDB Data Team • 11/06/2024
The vulnerability identified as CVE-2016-1826 represents a critical integer overflow flaw within the dynamic tracing framework of Apple's macOS operating system. This issue affects versions prior to macOS 10.11.5 and resides in the kernel-level dtrace implementation which is designed for system monitoring and debugging purposes. The vulnerability stems from inadequate input validation within the kernel's handling of tracepoint data structures, creating a scenario where malicious input can cause arithmetic overflow conditions that subsequently lead to memory corruption.
The technical exploitation of this vulnerability occurs when a crafted application attempts to manipulate the dtrace subsystem through specially constructed tracepoint arguments or data structures. When the kernel processes these malformed inputs, the integer overflow condition causes the system to allocate insufficient memory or overwrite critical kernel memory regions. This memory corruption can then be leveraged by an attacker to execute arbitrary code with kernel privileges, effectively elevating their execution context from user-level to privileged kernel-level access. The flaw specifically manifests during the processing of tracepoint data where integer variables overflow beyond their maximum representable values, creating exploitable memory layout conditions.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete control over the target system. Once successfully exploited, adversaries can bypass system security controls, install persistent backdoors, modify system files, and access sensitive data without detection. The vulnerability is particularly concerning because it requires no user interaction beyond executing the malicious application, making it a prime candidate for automated exploitation. The attack surface is broad as dtrace functionality is available system-wide and can be invoked by any application with appropriate permissions, though kernel-level execution requires the specific exploitation vector.
Mitigation strategies for CVE-2016-1826 primarily involve applying the official security update from Apple that patches the integer overflow condition in the dtrace kernel implementation. System administrators should immediately deploy macOS 10.11.5 or later versions that contain the necessary patches. Additionally, organizations should implement monitoring for suspicious dtrace activity and restrict application execution where possible. The vulnerability aligns with CWE-190, which specifically addresses integer overflow conditions, and falls under ATT&CK technique T1059.003 for command and scripting interpreter execution. Network administrators should monitor for potential exploitation attempts through unusual dtrace-related system calls and consider implementing application whitelisting policies to prevent execution of untrusted applications that might attempt to leverage this vulnerability.