CVE-2016-1760

Vulnerability

The XPC Services API in LaunchServices on Apple iOS prior to version 9.3 contains a flaw that allows a crafted application to bypass intended event-handler restrictions. This affects all devices running iOS versions before 9.3, including iPhone 4s and later, iPod touch (5th generation) and later, and iPad 2 and later [1]. The vulnerability resides in the inter-process communication mechanism used by LaunchServices to manage app events.

Exploitation

An attacker must first convince a user to install a maliciously crafted app on the device. Once installed, the app can exploit the XPC Services API to bypass the intended event-handler restrictions. The attacker does not require any additional privileges beyond the ability to run the crafted app. The exploitation sequence involves the app sending crafted XPC messages to LaunchServices, which then incorrectly processes them, allowing the attacker to modify events of arbitrary apps on the system [1].

Impact

Successful exploitation enables the attacker to modify events of any app on the device. This could lead to unauthorized actions within the context of the targeted app, such as altering user interactions, triggering unintended behaviors, or potentially leaking sensitive information through event manipulation. The attacker gains the ability to interfere with the normal event handling of other applications, but the scope is limited to event modification; no arbitrary code execution or privilege escalation is described in the available references [1].

Mitigation

Apple addressed this vulnerability in iOS 9.3, released on March 21, 2016. Users should update their devices to iOS 9.3 or later via the Settings > General > Software Update mechanism. No workarounds are documented for devices that cannot be updated. The vulnerability is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog as of the publication date [1].