CVE-2015-5923 in iOS
Summary
by MITRE
Apple iOS before 9.0.2 does not properly restrict the options available on the lock screen, which allows physically proximate attackers to read contact data or view photos via unspecified vectors.
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Analysis
by VulDB Data Team • 01/18/2018
The vulnerability identified as CVE-2015-5923 represents a significant security flaw in Apple iOS versions prior to 9.0.2 that compromises the integrity of device lock screen protections. This weakness stems from inadequate restrictions on lock screen options that permit unauthorized access to sensitive user data through physical proximity attacks. The vulnerability specifically affects iOS devices that fail to properly enforce access controls on lock screen interfaces, creating exploitable pathways for attackers who are physically present near the target device.
The technical implementation of this flaw involves insufficient validation of lock screen access controls and permission models that govern what information can be displayed or accessed while a device is locked. Attackers exploiting this vulnerability can leverage unspecified vectors to bypass normal security boundaries and gain access to contact information and photo data stored on the device. The vulnerability's classification aligns with CWE-284, which addresses improper access control mechanisms, and represents a failure in the operating system's privilege separation and access control enforcement. This weakness essentially undermines the fundamental security model that should protect user data when a device is not actively in use.
From an operational perspective, this vulnerability creates a substantial risk for users whose devices are within physical proximity of attackers. The attack vector requires only physical access to the device, making it particularly dangerous in environments where devices may be left unattended or where attackers can position themselves near targets. The impact extends beyond simple data exposure to include potential privacy violations and information disclosure that could lead to identity theft or other malicious activities. Security professionals should note that this vulnerability demonstrates the critical importance of proper lock screen implementation and the necessity of robust access control mechanisms in mobile operating systems. The threat model for this vulnerability aligns with ATT&CK technique T1550.001, which covers use of valid accounts, as attackers can leverage the device's own access controls against themselves.
The mitigation strategies for CVE-2015-5923 primarily involve updating affected iOS devices to version 9.0.2 or later, which implements proper lock screen restrictions and access control enforcement. Organizations should ensure comprehensive device management policies that include mandatory security updates and regular vulnerability assessments. System administrators should also consider implementing additional security controls such as device encryption, remote wipe capabilities, and user education programs about the risks of leaving devices unattended. The vulnerability highlights the importance of regular security patching and demonstrates how seemingly minor access control issues can create significant security risks in mobile environments where physical security cannot always be guaranteed.