CVE-2021-30714 in iOS
Summary
by MITRE • 09/08/2021
A race condition was addressed with improved state handling. This issue is fixed in iOS 14.6 and iPadOS 14.6. An application may be able to cause unexpected system termination or write kernel memory.
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Analysis
by VulDB Data Team • 09/08/2021
This vulnerability represents a classic race condition flaw that emerged from inadequate state management within the iOS operating system kernel. The issue stems from a timing dependency where multiple processes or threads can access shared resources simultaneously, creating opportunities for unpredictable behavior and system instability. Such race conditions typically occur when proper synchronization mechanisms fail to prevent concurrent access to critical system components, leading to potential exploitation by malicious applications seeking unauthorized system control.
The technical implementation of this vulnerability allows an application to manipulate kernel memory through improper state handling during concurrent operations. When multiple threads attempt to modify shared kernel data structures simultaneously, the absence of adequate locking mechanisms or atomic operations creates opportunities for memory corruption. This flaw specifically enables attackers to either force unexpected system termination through controlled crashes or directly write to kernel memory regions, potentially compromising system integrity and security boundaries.
From an operational impact perspective, this vulnerability presents significant risks to iOS device security and stability. The ability to cause unexpected system termination can be leveraged for denial of service attacks that disrupt legitimate user activities, while the kernel memory writing capability opens pathways for privilege escalation and persistent malware installation. Attackers could exploit this flaw to gain elevated privileges within the operating system, potentially leading to complete system compromise and unauthorized access to sensitive user data stored on the device.
The fix implemented in iOS 14.6 and iPadOS 14.6 addresses this issue through enhanced state handling mechanisms that properly synchronize concurrent access to shared kernel resources. This remediation follows established security practices aligned with CWE-362, which specifically addresses race conditions in concurrent programming environments. The solution likely incorporates improved mutex locking, atomic operations, or other synchronization primitives that prevent the simultaneous modification of critical system data structures during concurrent execution.
Organizations and users should prioritize immediate deployment of iOS 14.6 updates to mitigate this vulnerability, as it represents a significant security risk within the mobile operating system ecosystem. The remediation process aligns with ATT&CK framework techniques related to privilege escalation and defense evasion, where attackers might leverage such vulnerabilities to establish persistent access or conceal malicious activities within the system. Security teams should monitor for potential exploitation attempts and maintain awareness of how this flaw could be combined with other attack vectors to achieve more sophisticated compromise objectives.
This vulnerability class demonstrates the critical importance of proper synchronization in kernel-level programming and highlights the necessity of comprehensive security testing for concurrent execution scenarios. The race condition represents a fundamental architectural weakness that can have cascading effects on system stability and security posture, emphasizing the need for robust state management practices throughout operating system development cycles to prevent similar issues from emerging in future releases.