CVE-2015-7000 in iOS
Summary
by MITRE
Notification Center in Apple iOS before 9.1 mishandles changes to "Show on Lock Screen" settings, which allows physically proximate attackers to obtain sensitive information by looking for a (1) Phone or (2) Messages notification on the lock screen soon after a setting was disabled.
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Analysis
by VulDB Data Team • 06/24/2022
The vulnerability identified as CVE-2015-7000 represents a critical security flaw in Apple iOS versions prior to 9.1, specifically within the Notification Center component. This issue stems from improper handling of user privacy settings related to notification display on the lock screen. The flaw creates a window of opportunity for attackers who are physically present near the target device to exploit a timing-based information disclosure vulnerability. The vulnerability operates through a race condition where the system fails to immediately enforce the new security settings, allowing notifications to persist on the lock screen even after users have explicitly disabled their display.
The technical implementation of this vulnerability involves the Notification Center's failure to synchronize its display state with the underlying security settings changes. When a user modifies the "Show on Lock Screen" preference, the system should immediately purge or suppress any notifications that were previously visible on the lock screen. However, the iOS implementation does not properly handle this transition, creating a temporal gap where notifications can still be viewed by unauthorized individuals. This behavior violates fundamental security principles of access control and information flow management, as it allows unauthorized parties to gain access to potentially sensitive data through simple observation.
From an operational perspective, this vulnerability poses significant risks to user privacy and data protection, particularly in environments where physical proximity attacks are possible. Attackers can exploit this flaw by observing notifications that contain sensitive information such as phone calls or messages, which may include personal communications, business data, or other confidential information. The vulnerability specifically targets the timing aspect of system security controls, where the window between setting modification and effective enforcement creates an exploitable condition. This type of vulnerability aligns with CWE-284, which addresses improper access control, and represents a classic case of temporal security weakness that can be exploited through physical access attacks.
The impact of this vulnerability extends beyond simple information disclosure, as it undermines the fundamental security model of mobile operating systems. Users who believe they have protected their privacy by disabling lock screen notifications may find their assumptions violated due to this implementation flaw. The vulnerability is particularly concerning in corporate environments where mobile devices contain sensitive business information, and in personal contexts where individuals may be targeted by opportunistic attackers. The attack vector requires only physical proximity, making it accessible to anyone who can observe the target device, which significantly broadens the potential threat surface. This vulnerability demonstrates the importance of proper state management in security-critical components and highlights the need for comprehensive testing of security controls under various operational conditions.
Mitigation strategies for CVE-2015-7000 primarily involve updating to iOS 9.1 or later versions where Apple implemented proper synchronization of notification settings with lock screen display behavior. Organizations should enforce mandatory security updates and consider implementing additional physical security measures such as device encryption and screen locks to provide defense-in-depth. System administrators should also educate users about the importance of immediate security setting changes and the potential risks of leaving devices unattended. The vulnerability serves as a reminder of the critical importance of proper state management in security implementations and the need for thorough testing of security controls under various operational scenarios. This case study exemplifies the ATT&CK framework concept of privilege escalation through local exploitation, where an attacker leverages a system implementation flaw to gain unauthorized access to information.