CVE-2016-7651 in watchOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.2 is affected. watchOS before 3.1.1 is affected. The issue involves the "Accounts" component, which allows local users to bypass intended authorization restrictions by leveraging the mishandling of an app uninstall.
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Analysis
by VulDB Data Team • 11/03/2022
The vulnerability identified as CVE-2016-7651 represents a critical authorization bypass flaw within Apple's Accounts component affecting multiple operating systems including iOS versions prior to 10.2 and watchOS versions prior to 3.1.1. This security weakness stems from improper handling of application uninstallation processes which creates opportunities for local attackers to circumvent intended access controls and authorization mechanisms. The vulnerability specifically targets the way the system manages account credentials and permissions when applications are removed from the device, creating a persistent security gap that remains active even after legitimate uninstallation procedures.
The technical exploitation of this vulnerability occurs through a sophisticated manipulation of the Accounts framework's internal state management during application removal operations. When users uninstall applications, the system should properly invalidate associated account credentials and revoke access permissions to prevent unauthorized continued access. However, the flaw allows malicious actors to leverage the incomplete cleanup process to maintain access to restricted resources, effectively bypassing the intended authorization boundaries that should be enforced upon application removal. This represents a fundamental failure in the privilege management system where the accounts component fails to properly enforce access controls during the uninstallation lifecycle phase.
From an operational impact perspective, this vulnerability creates significant security risks for affected Apple device users as it enables persistent unauthorized access to account-based services and data. Local attackers can exploit this flaw to maintain access to sensitive information, potentially including email accounts, cloud storage services, and other credential-protected resources that were previously accessible only through legitimate application usage. The persistence of this vulnerability across multiple Apple platforms demonstrates the widespread nature of the flaw and the potential for extensive compromise across different device types within the same user environment. This authorization bypass capability undermines the fundamental security model that Apple implements to protect user credentials and access permissions.
The vulnerability aligns with CWE-284, which addresses improper access control issues, and demonstrates characteristics consistent with privilege escalation vulnerabilities within mobile operating system frameworks. From an ATT&CK framework perspective, this flaw corresponds to techniques involving privilege escalation and persistence mechanisms, as attackers can maintain access beyond normal application lifecycle boundaries. The exploitation requires local access to the device, making it a low-privilege but high-impact vulnerability that can be leveraged by malware or malicious applications already present on the device. Security professionals should consider this vulnerability as part of broader mobile device security assessments, particularly focusing on application lifecycle management and credential handling processes.
Mitigation strategies for CVE-2016-7651 primarily involve updating affected Apple devices to the patched versions, specifically iOS 10.2 and watchOS 3.1.1, which contain the necessary fixes for the Accounts component. Organizations should implement comprehensive patch management policies to ensure all affected devices receive updates promptly, particularly in enterprise environments where multiple Apple devices may be in use. System administrators should also consider monitoring for unusual account access patterns that might indicate exploitation attempts, as the vulnerability creates persistent access opportunities that could be difficult to detect through normal security auditing processes. Additionally, users should be educated about the importance of keeping their devices updated and should be aware of the potential risks associated with using unpatched operating systems in environments where sensitive data may be accessible through account-based services.