CVE-2016-4721 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.1 is affected. macOS before 10.12.1 is affected. The issue involves the "IDS - Connectivity" component, which allows man-in-the-middle attackers to spoof calls via a "switch caller" notification.
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Analysis
by VulDB Data Team • 08/16/2020
The vulnerability identified as CVE-2016-4721 represents a significant security flaw within Apple's ecosystem affecting multiple operating systems including iOS versions prior to 10.1 and macOS versions prior to 10.12.1. This issue resides within the IDS - Connectivity component of Apple's infrastructure, specifically targeting the communication protocols that govern how devices handle caller identification and call routing. The vulnerability manifests through a sophisticated man-in-the-middle attack vector that enables malicious actors to manipulate the caller identification system and potentially intercept or redirect communications.
The technical implementation of this vulnerability stems from insufficient authentication mechanisms within the IDS - Connectivity framework, which is responsible for managing the secure communication channels between Apple devices and their respective networks. Attackers can exploit this weakness by intercepting legitimate "switch caller" notifications and replacing them with forged messages that appear to originate from trusted sources. This manipulation allows adversaries to present false caller information while maintaining the appearance of legitimate communication, effectively bypassing the security controls designed to verify caller identity and authentication.
From an operational perspective, this vulnerability poses substantial risks to user privacy and security as it enables attackers to spoof phone calls and potentially gain unauthorized access to sensitive information. The impact extends beyond simple caller ID deception, as successful exploitation could allow attackers to redirect calls to malicious numbers, intercept voice communications, or even facilitate further social engineering attacks. The vulnerability particularly affects users who rely on Apple's ecosystem for secure communications, as it undermines the fundamental trust model that governs how devices authenticate and verify incoming calls.
The attack vector for this vulnerability aligns with the MITRE ATT&CK framework's tactics for privilege escalation and credential access, specifically targeting the communication protocols and network infrastructure that Apple devices use to establish trust relationships. This weakness creates an entry point for attackers to establish persistent access to communication channels, potentially enabling long-term surveillance or data interception activities. The vulnerability also relates to CWE-287, which addresses improper authentication issues in software systems, particularly in contexts where device-to-device communication is involved.
Organizations and individual users should implement immediate mitigations including updating to the affected Apple operating systems as soon as possible, ensuring that all devices are running the latest security patches. Network administrators should consider implementing additional monitoring of communication protocols to detect anomalous caller identification patterns that may indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date security controls, particularly in mobile and enterprise environments where Apple devices are prevalent and communication security is paramount for protecting sensitive business and personal information.