CVE-2015-1063 in iOS
Summary
by MITRE
CoreTelephony in Apple iOS before 8.2 allows remote attackers to cause a denial of service (NULL pointer dereference and device restart) via a Class 0 SMS message.
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Analysis
by VulDB Data Team • 04/15/2022
The vulnerability identified as CVE-2015-1063 resides within the CoreTelephony framework of Apple iOS operating systems prior to version 8.2. This flaw manifests as a NULL pointer dereference condition that occurs when processing Class 0 SMS messages, which are typically used for emergency alerts and system notifications. The issue represents a fundamental flaw in how the telephony subsystem handles specific types of incoming messages without proper input validation or error handling mechanisms. Class 0 SMS messages are designed to be displayed immediately without being stored in the device's message inbox, making them particularly critical for emergency communications but also potentially dangerous when exploited.
The technical exploitation of this vulnerability occurs when an attacker sends a specially crafted Class 0 SMS message to a vulnerable iOS device. The CoreTelephony framework fails to properly validate the message structure and content before attempting to process it, leading to a NULL pointer dereference error. This memory access violation causes the telephony service to crash and subsequently restarts the entire device, resulting in a denial of service condition that renders the mobile device temporarily unusable. The vulnerability operates at the kernel level within the telephony subsystem, making it particularly impactful as it affects the fundamental communication capabilities of the device.
From an operational perspective, this vulnerability creates significant security implications for mobile device users and organizations relying on iOS devices for communication. The remote nature of the attack means that adversaries can exploit this flaw without physical access to the target device, making it particularly concerning for enterprise environments where mobile devices handle sensitive information. The device restart caused by this vulnerability can result in loss of ongoing communications, potential data loss, and disruption of critical business operations. Additionally, the automatic nature of the exploit means that users may not even realize their device has been compromised until the service interruption occurs, providing attackers with a stealthy method of disabling targeted devices.
The vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions, and demonstrates characteristics consistent with ATT&CK technique T1499.002 which involves network denial of service attacks. Organizations should implement immediate mitigations including updating to iOS 8.2 or later versions where the vulnerability has been patched, and consider network-level filtering of Class 0 SMS messages when possible. Mobile device management solutions should also be configured to monitor for unusual telephony service restarts that could indicate exploitation attempts. The patch released by Apple addressed the input validation issues within the CoreTelephony framework, ensuring proper handling of malformed Class 0 SMS messages through enhanced error checking and memory management protocols.