CVE-2016-7646 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-2016-7646 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 weakness resides in the core web browsing component responsible for processing and rendering web content across Apple's ecosystem, making it a significant attack vector for remote code execution. The vulnerability stems from improper memory handling within WebKit's JavaScript engine, specifically when processing malformed web content that triggers buffer overflows or use-after-free conditions. According to CWE classification, this vulnerability maps to CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions, both of which are common precursors to arbitrary code execution exploits.
The operational impact of this vulnerability extends far beyond simple application crashes, as it enables remote attackers to execute arbitrary code on affected systems without user interaction. This means that simply visiting a malicious website could result in complete system compromise, allowing attackers to install malware, steal sensitive data, or establish persistent backdoors. The memory corruption aspects of this vulnerability can manifest as either heap-based or stack-based buffer overflows, depending on how the malicious web content is crafted to exploit the underlying WebKit implementation. Attackers could leverage this vulnerability to bypass security mechanisms such as sandboxing, code signing requirements, and other system protections that Apple implements to secure its operating environments.
The exploitation of CVE-2016-7646 aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to initial access through malicious websites and privilege escalation via code execution. The vulnerability's remote nature means that attackers can conduct large-scale campaigns without requiring physical access to target devices, making it particularly dangerous for enterprise environments where users may inadvertently visit compromised websites. Security researchers have documented that this vulnerability was actively exploited in the wild prior to the release of security patches, with threat actors creating malicious web pages specifically designed to target the memory corruption flaw. Organizations should consider this vulnerability as part of a broader threat landscape where browser-based attacks represent one of the most common attack vectors for advanced persistent threats, particularly when targeting Apple devices that were not properly updated with the security patches addressing this specific WebKit flaw.
Mitigation strategies for CVE-2016-7646 require immediate patch deployment across all affected Apple products, with particular emphasis on iOS devices, Safari browsers, and iCloud and iTunes applications. System administrators should implement network-based protections including web filtering solutions and intrusion prevention systems that can detect and block known malicious web content targeting this vulnerability. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping their Apple devices updated with the latest security patches. The vulnerability demonstrates the critical importance of maintaining up-to-date software across all system components, as even a single unpatched browser component can provide attackers with a complete entry point into Apple ecosystems. Organizations should also consider implementing additional security controls such as web application firewalls and monitoring for suspicious network traffic patterns that may indicate exploitation attempts.