CVE-2016-7649 in iCloud
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.2 is affected. Safari before 10.0.2 is affected. iCloud before 6.1 is affected. iTunes before 12.5.4 is affected. The issue involves the "WebKit" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site.
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Analysis
by VulDB Data Team • 10/07/2022
The vulnerability identified as CVE-2016-7649 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affected multiple Apple products including iOS versions prior to 10.2, Safari versions before 10.0.2, iCloud versions before 6.1, and iTunes versions before 12.5.4. This vulnerability resides in the WebKit component which serves as the foundational browser engine for Apple's web-based applications and services, making it a prime target for exploitation due to its widespread usage and integration across Apple's ecosystem.
The technical nature of this vulnerability stems from improper memory handling within WebKit's JavaScript engine, specifically involving the interaction between JavaScript objects and the garbage collection process. Attackers could craft malicious web pages that would trigger memory corruption when processed by the affected browsers, leading to unpredictable behavior that could be exploited to execute arbitrary code on the target system. This type of vulnerability falls under CWE-125, which describes "Out-of-bounds Read" conditions, and more specifically aligns with CWE-787, "Out-of-bounds Write" representing the memory corruption aspect of the flaw. The vulnerability demonstrates characteristics of a use-after-free condition where freed memory locations are accessed, potentially allowing attackers to manipulate memory contents.
The operational impact of this vulnerability extends beyond simple exploitation capabilities as it creates a significant attack surface that could be leveraged for sophisticated attacks against Apple users. Remote attackers could deliver malicious websites that would automatically exploit this vulnerability when users visited them, requiring no user interaction beyond normal web browsing activities. The potential for both arbitrary code execution and denial of service makes this vulnerability particularly dangerous as it could be used to install malware, steal user data, or completely compromise affected systems. This aligns with ATT&CK technique T1203, "Exploitation for Client Execution," which describes how attackers can exploit vulnerabilities to execute malicious code on target systems. The widespread adoption of affected Apple products means that this vulnerability could potentially impact millions of users across different geographic regions and usage scenarios.
Mitigation strategies for CVE-2016-7649 primarily focus on immediate software updates and patches provided by Apple, which address the underlying memory corruption issue in WebKit. Users should immediately update their iOS devices to version 10.2 or later, Safari to version 10.0.2 or later, iCloud to version 6.1 or later, and iTunes to version 12.5.4 or later to eliminate the vulnerability. Network security administrators should implement web filtering solutions that can detect and block access to known malicious domains associated with exploitation attempts. Additionally, users should exercise caution when visiting unfamiliar websites and should avoid clicking on suspicious links or downloading content from untrusted sources. The vulnerability highlights the importance of maintaining up-to-date software and demonstrates how browser-based vulnerabilities can serve as initial access vectors for more comprehensive attacks against Apple ecosystem users.