CVE-2015-1099 in Watch OS
Summary
by MITRE
Race condition in the setreuid system-call implementation in the kernel in Apple iOS before 8.3, Apple OS X before 10.10.3, and Apple TV before 7.2 allows attackers to cause a denial of service via a crafted app.
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Analysis
by VulDB Data Team • 12/01/2024
The vulnerability identified as CVE-2015-1099 represents a critical race condition within the kernel's setreuid system call implementation affecting multiple Apple operating systems. This flaw exists in the way the kernel handles privilege escalation operations when transitioning from one user ID to another, creating a temporal window where concurrent processes can exploit inconsistent state management. The race condition occurs during the execution of setreuid calls, which are fundamental system operations used to change the real user ID of a process, making this vulnerability particularly dangerous as it can be leveraged by malicious applications to manipulate system behavior.
The technical implementation of this vulnerability stems from improper synchronization mechanisms within the kernel's privilege management subsystem. When a process invokes setreuid, the kernel must validate permissions and update internal process structures while maintaining consistency across multiple execution contexts. The race condition manifests when multiple threads or processes attempt to modify the same user ID state simultaneously, leading to unpredictable behavior where the kernel may execute operations with incorrect privilege levels or fail to properly enforce access controls. This flaw is categorized under CWE-362, which specifically addresses race conditions in concurrent systems, and aligns with ATT&CK technique T1068, which covers local privilege escalation through kernel vulnerabilities.
The operational impact of CVE-2015-1099 extends beyond simple denial of service scenarios, as it creates opportunities for more sophisticated attacks that could potentially compromise system integrity. While the primary exploitation vector described involves denial of service through crafted applications, the underlying race condition could theoretically be extended to allow privilege escalation or information disclosure if attackers can manipulate the timing of concurrent operations. The vulnerability affects a broad range of Apple products including iOS devices, macOS systems, and Apple TV receivers, making it particularly concerning for enterprise environments where these systems are prevalent. The specific versions impacted demonstrate that Apple had not yet addressed this temporal inconsistency in their kernel implementations, creating a window of exposure for users of affected releases.
Mitigation strategies for this vulnerability require immediate system updates to the patched versions of affected operating systems, specifically iOS 8.3, OS X 10.10.3, and Apple TV 7.2. System administrators should prioritize deployment of these security patches as they address the root cause of the race condition through improved kernel synchronization mechanisms. Additionally, organizations should implement monitoring for suspicious process behavior that might indicate exploitation attempts, particularly around privilege escalation operations. The fix likely involves implementing proper locking mechanisms or atomic operations within the setreuid system call implementation to prevent concurrent access to the user ID state management functions, ensuring that privilege transitions occur in a consistent and predictable manner. Security teams should also consider implementing application whitelisting policies to limit the potential impact of malicious applications that might attempt to exploit this vulnerability, particularly in environments where immediate patch deployment is not immediately feasible.