CVE-2012-3736 in iOS
Summary
by MITRE
The Passcode Lock implementation in Apple iOS before 6 allows physically proximate attackers to bypass an intended passcode requirement via vectors related to ending a FaceTime call.
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Analysis
by VulDB Data Team • 04/13/2021
The vulnerability described in CVE-2012-3736 represents a significant security flaw in Apple iOS versions prior to version 6, specifically within the passcode lock implementation. This weakness allows attackers who are physically close to a target device to circumvent the intended security measures that should protect against unauthorized access. The vulnerability manifests through a specific interaction pattern involving FaceTime calls, where the attacker can exploit the device's handling of call termination to gain access to the locked system without proper authentication.
The technical flaw resides in how iOS manages the transition between active FaceTime sessions and the device's lock screen state. When a FaceTime call ends, the system should properly enforce the passcode requirement to re-activate the device's security protections. However, the implementation contains a logic error that allows the device to remain accessible without requiring the passcode, particularly when the device is in a state where the FaceTime interface is still present or transitioning. This behavior creates a window of opportunity for attackers to access the device without proper authorization, effectively bypassing the security controls designed to protect user data and privacy.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it demonstrates a fundamental weakness in the device's security architecture. An attacker with physical proximity to a victim's device can exploit this flaw to access sensitive information, make unauthorized transactions, or perform other malicious activities without the need for sophisticated techniques or tools. The vulnerability is particularly concerning because it operates within the normal usage patterns of FaceTime, making it difficult for users to recognize the security compromise. The risk is elevated when considering that FaceTime calls are commonly used in public settings where physical proximity attacks are feasible.
This vulnerability aligns with CWE-284, which addresses improper access control issues in software systems, and represents a classic case of inadequate privilege management. The flaw enables an attacker to escalate their privileges without proper authentication, effectively creating a backdoor through legitimate device functionality. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, specifically leveraging the device's legitimate call management features to bypass security controls. The attack vector is particularly relevant to the T1547.001 technique, which involves the exploitation of legitimate credentials and system access patterns.
Mitigation strategies for this vulnerability require immediate system updates to iOS version 6 or later, where Apple implemented proper fixes to the FaceTime call handling and passcode enforcement mechanisms. Users should also maintain awareness of their device's security state and avoid leaving devices unattended in public spaces where physical proximity attacks could occur. Organizations should implement comprehensive mobile device management policies that enforce automatic updates and security patches. The vulnerability highlights the importance of proper security testing for all device functionalities, particularly those involving user authentication and session management. Additionally, system administrators should consider implementing additional security controls such as remote wipe capabilities and enhanced monitoring for suspicious access patterns. The incident underscores the critical need for continuous security assessment and the importance of addressing vulnerabilities in mobile operating systems that directly impact user privacy and data protection.