CVE-2017-13905 in macOS
Summary
by MITRE • 12/23/2021
A race condition was addressed with additional validation. This issue is fixed in tvOS 11.2, iOS 11.2, macOS High Sierra 10.13.2, Security Update 2017-002 Sierra, and Security Update 2017-005 El Capitan, watchOS 4.2. An application may be able to gain elevated privileges.
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Analysis
by VulDB Data Team • 12/27/2021
This vulnerability represents a race condition that existed within Apple's operating systems, specifically affecting iOS, tvOS, macOS, and watchOS platforms. The flaw emerged from insufficient validation mechanisms during critical system operations, creating a window where malicious applications could exploit temporal inconsistencies in privilege management. The race condition occurred when multiple processes or threads attempted to access shared resources simultaneously, leading to unpredictable behavior that could be leveraged by attackers to escalate their privileges from standard user level to administrative access. This type of vulnerability falls under the broader category of concurrency issues that are classified as CWE-362 in the Common Weakness Enumeration framework, which specifically addresses "Concurrent Execution using Shared Resource with Improper Synchronization."
The operational impact of this vulnerability was significant as it provided attackers with a pathway to bypass normal security controls that typically prevent unauthorized privilege escalation. An application running with standard user permissions could potentially exploit this race condition to execute code with elevated privileges, effectively undermining the fundamental security model of Apple's operating systems. The vulnerability was particularly concerning because it affected multiple platform versions simultaneously, suggesting a systemic issue in the underlying kernel or system libraries that govern privilege management and resource access. Attackers could potentially use this flaw to install malicious software, modify system files, or access sensitive user data without proper authorization, making it a critical security concern for all affected devices.
Apple addressed this vulnerability through comprehensive system updates that implemented additional validation checks and improved synchronization mechanisms to prevent the race condition from being exploited. The fixes included enhanced kernel-level protections that ensure proper handling of concurrent access to critical system resources and strengthened privilege validation routines. These updates were released as part of the respective security updates for each operating system, with specific versions mentioned including iOS 11.2, tvOS 11.2, macOS High Sierra 10.13.2, and the corresponding security updates for Sierra and El Capitan. The mitigation strategy focused on eliminating the temporal window where the race condition could be exploited, thereby preventing unauthorized privilege escalation. From an ATT&CK framework perspective, this vulnerability would map to privilege escalation techniques and could be categorized under T1068 for 'Exploitation for Privilege Escalation' with potential use of T1059 for 'Command and Scripting Interpreter' to execute malicious code once elevated privileges were obtained. Organizations should prioritize applying these security updates immediately to protect their systems from potential exploitation, as the vulnerability could be leveraged by sophisticated attackers to establish persistent access to affected devices.