CVE-2013-5147 in iOS
Summary
by MITRE
Passcode Lock in Apple iOS before 7 does not properly manage the lock state, which allows physically proximate attackers to bypass an intended passcode requirement by leveraging a race condition involving phone calls and ejection of a SIM card.
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Analysis
by VulDB Data Team • 10/18/2024
The vulnerability described in CVE-2013-5147 represents a critical security flaw in Apple iOS versions prior to 7.0, specifically targeting the passcode lock mechanism that governs device access control. This weakness stems from improper management of the device's lock state during specific operational conditions, creating a window of opportunity for unauthorized access. The vulnerability manifests when an attacker is physically proximate to a target device and can exploit a race condition that occurs during concurrent phone call operations and SIM card ejection events. The flaw fundamentally undermines the intended security model of mobile device encryption and authentication, as it allows bypassing the passcode requirement through legitimate device interactions rather than through direct exploitation.
The technical implementation of this vulnerability involves a race condition within iOS's lock state management system. When a phone call is active and simultaneously a SIM card is ejected or removed from the device, the operating system fails to properly synchronize the lock state transitions. This creates a temporal gap where the device temporarily loses its enforced passcode protection while maintaining active phone call functionality. The race condition occurs because the system does not adequately coordinate between the telephony subsystem and the security subsystem during these specific transitions, allowing an attacker to exploit the timing window to access the device without proper authentication. The flaw exists at the operating system level and affects the fundamental security architecture that governs device access controls.
The operational impact of this vulnerability extends beyond simple unauthorized access to potentially exposing sensitive data stored on iOS devices. Attackers can leverage this flaw to gain access to personal information, financial data, communication records, and other confidential material without the need for sophisticated exploitation techniques. The vulnerability is particularly concerning because it requires minimal skill and access to exploit, as attackers only need to be physically proximate to the target device and perform simple actions such as initiating a phone call and removing the SIM card. This makes the attack vector highly practical in real-world scenarios where attackers can observe target devices in public spaces or workplace environments. The vulnerability affects all iOS versions prior to 7.0, impacting millions of devices that were widely deployed in enterprise and consumer environments.
The security implications of this vulnerability align with CWE-362, which describes a race condition that allows multiple threads or processes to access shared resources concurrently, leading to inconsistent or insecure states. This particular flaw represents a temporal race condition in the security subsystem where the device's lock state management becomes inconsistent during specific operational transitions. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, specifically leveraging system-level weaknesses to bypass authentication mechanisms. The attack pattern demonstrates how legitimate device functionality can be abused to undermine security controls, representing a sophisticated form of attack that exploits the intended behavior of the system rather than its implementation flaws.
Mitigation strategies for this vulnerability required immediate system updates to iOS version 7.0 or later, where Apple implemented comprehensive fixes to the lock state management system. The update addressed the race condition by improving synchronization between telephony and security subsystems, ensuring that device lock states remain consistent during phone call operations and SIM card transitions. Organizations should have implemented comprehensive patch management procedures to ensure all devices were updated promptly, as the vulnerability remained exploitable until the system was patched. Additional protective measures included enabling automatic updates, implementing device management policies, and conducting security awareness training to educate users about the risks of physical proximity attacks. The vulnerability highlighted the importance of proper synchronization in security-critical systems and demonstrated how seemingly benign device operations could create security weaknesses when not properly coordinated with authentication mechanisms.