CVE-2015-1106 in iOS
Summary
by MITRE
The QuickType feature in the Keyboards subsystem in Apple iOS before 8.3 allows physically proximate attackers to discover passcodes by reading the lock screen during use of a Bluetooth keyboard.
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Analysis
by VulDB Data Team • 05/03/2022
The vulnerability CVE-2015-1106 represents a significant security flaw in Apple iOS versions prior to 8.3, specifically within the QuickType predictive text feature of the keyboard subsystem. This vulnerability exposes users to a sophisticated attack vector where adversaries can exploit the proximity-based data collection mechanisms to extract passcodes from lock screens. The issue stems from the way iOS handles predictive text input when Bluetooth keyboards are connected, creating an unintended information disclosure channel that bypasses normal security controls designed to protect device access.
The technical implementation flaw occurs in the Keyboards subsystem where QuickType functionality, which normally provides predictive text suggestions to improve typing efficiency, fails to properly isolate sensitive input contexts. When a Bluetooth keyboard is connected to an iOS device, the system's predictive algorithms continue to process input from the lock screen, including passcode entry sequences. This creates a scenario where the predictive text engine, designed to assist with typing, inadvertently reveals information about the user's passcode through the QuickType suggestions that appear on the screen. The vulnerability is particularly concerning because it requires minimal physical proximity and no authentication credentials to exploit, making it accessible to attackers in close physical proximity to the target device.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally undermines the security model of iOS device lock screens. Attackers can leverage this flaw to systematically discover passcodes through repeated use of the predictive text feature, effectively reducing the security of lock screen protection to a simple guessing game. The vulnerability affects all iOS versions before 8.3, leaving millions of devices exposed to potential compromise. From an attacker's perspective, this represents a low-effort, high-impact method of bypassing device security, as the attack requires only a Bluetooth keyboard and physical proximity to the target device. The threat model aligns with ATT&CK technique T1556.004 for credential access through input capture, and the vulnerability's nature as a predictive text bypass fits within CWE-200 for exposure of sensitive information.
Mitigation strategies for CVE-2015-1106 focus primarily on updating to iOS 8.3 or later versions, which Apple released to address this specific vulnerability. Users should immediately apply the security update to ensure their devices receive the patched keyboard subsystem that properly isolates lock screen input contexts from predictive text processing. Organizations should implement comprehensive mobile device management policies that enforce automatic security updates and regularly audit device configurations to ensure all endpoints are protected against this vulnerability. Additionally, users should be educated about the risks of using Bluetooth keyboards with devices containing sensitive information, particularly in public or shared environments where physical proximity attacks may occur. The vulnerability demonstrates the importance of proper input context handling in mobile operating systems and highlights how seemingly benign features can create security risks when not properly isolated from sensitive operations. Security practitioners should also consider implementing network monitoring to detect unusual Bluetooth device pairing activities that might indicate potential exploitation attempts.