CVE-2013-5164 in iOS
Summary
by MITRE
Multiple race conditions in the Phone app in Apple iOS before 7.0.3 allow physically proximate attackers to bypass the locked state, and dial the telephone numbers in arbitrary Contacts entries, by visiting the Contacts pane.
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Analysis
by VulDB Data Team • 05/31/2021
The vulnerability described in CVE-2013-5164 represents a critical security flaw in Apple iOS versions prior to 7.0.3 that exploits race conditions within the Phone application's locked screen functionality. This vulnerability specifically targets the interaction between the device's lock screen protection mechanisms and the Contacts application, creating an exploitable pathway for attackers who are physically present with the target device. The flaw enables unauthorized access to phone dialing capabilities even when the device is secured with a passcode or biometric authentication, fundamentally undermining the device's security model.
The technical implementation of this vulnerability stems from race conditions occurring in the Phone app's handling of user interface transitions and authentication state checks. When a user navigates to the Contacts pane while the device is locked, the system fails to properly validate the authentication status before allowing access to dialing functions. This race condition manifests as a timing window where the system momentarily allows access to Contacts entries that should be protected by the lock screen, enabling attackers to initiate phone calls to any number stored in the device's contact list. The vulnerability specifically leverages the physical proximity requirement, as attackers must be in direct contact with the device to exploit the flaw.
Operationally, this vulnerability creates significant security implications for iOS users, as it allows attackers to bypass the fundamental security protections designed to prevent unauthorized access to sensitive communication functions. The ability to dial arbitrary contact numbers without authentication presents risks for privacy violations, potential harassment, and unauthorized communication attempts that could be used for social engineering or malicious activities. The vulnerability essentially transforms the locked phone into a tool that can be used for unauthorized dialing, potentially leading to financial losses through premium rate number calls or privacy breaches through contact list enumeration.
This vulnerability maps to CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) race conditions, and aligns with ATT&CK technique T1056.001 for Input Capture through the unauthorized access to phone dialing functions. The attack vector requires physical proximity and involves a simple interaction with the device's user interface, making it particularly concerning for mobile device security. The vulnerability demonstrates the importance of proper state validation in mobile operating systems and highlights how seemingly minor timing issues in application logic can create significant security breaches.
Mitigation strategies for CVE-2013-5164 require immediate system updates to iOS version 7.0.3 or later, where Apple implemented proper synchronization mechanisms to prevent the race conditions that enabled this attack. Users should also consider enabling additional security measures such as biometric authentication with strong passcodes, and regularly updating their devices to ensure protection against similar vulnerabilities. Organizations should implement device management policies that enforce automatic security updates and educate users about the risks of leaving devices unattended in public spaces where physical access could enable exploitation of such vulnerabilities.