CVE-2017-13864 in iTunes
Summary
by MITRE
An issue was discovered in certain Apple products. iCloud before 7.2 on Windows is affected. iTunes before 12.7.2 on Windows is affected. The issue involves the "APNs Server" component. It allows man-in-the-middle attackers to track users by leveraging mishandling of client certificates.
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Analysis
by VulDB Data Team • 01/27/2021
The vulnerability identified as CVE-2017-13864 represents a critical security flaw in Apple's ecosystem affecting Windows implementations of iCloud and iTunes software versions prior to 7.2 and 12.7.2 respectively. This weakness resides within the APNs Server component which serves as the foundation for Apple Push Notification service delivery. The issue stems from inadequate handling of client certificates during the authentication process, creating a significant attack vector that compromises user privacy and tracking capabilities. The vulnerability specifically impacts the secure communication channel between Apple's notification servers and Windows client applications, potentially allowing malicious actors to intercept and monitor user activities.
The technical exploitation of this vulnerability occurs through man-in-the-middle attack techniques where adversaries position themselves between the affected Apple applications and Apple's push notification servers. The mishandling of client certificates enables attackers to establish fraudulent connections while maintaining the appearance of legitimate communication. This flaw directly relates to CWE-295 which addresses improper certificate validation and CWE-308 which covers the use of weak or predictable cryptographic functions in authentication mechanisms. The vulnerability's impact extends beyond simple data interception as it provides persistent tracking capabilities that can be leveraged for comprehensive user behavior monitoring and profiling.
From an operational perspective, this vulnerability creates substantial risk for users of affected Apple software on Windows platforms. The tracking capabilities enabled by this flaw could allow attackers to monitor user activities across multiple applications and services, potentially exposing sensitive personal information and location data. The attack surface is particularly concerning given the widespread use of iCloud and iTunes services on Windows systems, making this vulnerability attractive to threat actors seeking persistent surveillance capabilities. The vulnerability's exploitation does not require sophisticated techniques but rather relies on standard man-in-the-middle attack methodologies that can be automated and deployed at scale.
Security mitigations for CVE-2017-13864 primarily involve updating to the patched versions of iCloud and iTunes software as provided by Apple. Users should immediately upgrade to iCloud version 7.2 and iTunes version 12.7.2 or later to address the certificate handling issues. Network administrators should implement additional monitoring for unusual certificate validation patterns and consider deploying network segmentation to limit exposure. The vulnerability's classification under ATT&CK technique T1046 for network service scanning and T1071 for application layer protocol communication demonstrates its potential for broader exploitation within network environments. Organizations should also review their certificate management policies and ensure proper validation procedures are in place to prevent similar issues in other components of their infrastructure.