CVE-2017-7111 in tvOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11 is affected. Safari before 11 is affected. iCloud before 7.0 on Windows is affected. iTunes before 12.7 on Windows is affected. tvOS before 11 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 • 01/20/2021
The vulnerability identified as CVE-2017-7111 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affected multiple Apple platforms and applications. This vulnerability resides in the core web browsing component that powers Safari, iOS web views, and various other Apple applications that utilize WebKit for web content rendering. The flaw specifically manifests in how WebKit handles certain crafted web content, creating opportunities for remote code execution or system instability. The vulnerability affects iOS versions prior to 11.0, Safari versions prior to 11.0, iCloud versions prior to 7.0 on Windows, iTunes versions prior to 12.7 on Windows, and tvOS versions prior to 11.0, indicating a widespread impact across Apple's ecosystem.
The technical nature of this vulnerability stems from improper memory handling within WebKit's JavaScript engine and rendering components. Attackers can exploit this flaw by crafting malicious web pages that trigger memory corruption when processed by the affected WebKit implementations. The memory corruption occurs during the parsing or execution of specific JavaScript code or HTML elements, leading to unpredictable behavior that can be leveraged for remote code execution. This type of vulnerability typically falls under CWE-125, which describes out-of-bounds read conditions, and may also involve CWE-787, representing out-of-bounds write conditions that can lead to memory corruption. The vulnerability's exploitation requires no user interaction beyond visiting a malicious website, making it particularly dangerous as it can be delivered through phishing campaigns, malicious advertisements, or compromised legitimate websites.
The operational impact of CVE-2017-7111 extends beyond simple application crashes or denial of service conditions. When successfully exploited, this vulnerability allows attackers to execute arbitrary code with the privileges of the affected application, potentially leading to complete system compromise. The attack surface is extensive given that WebKit is used across numerous Apple applications, meaning that a single exploit could potentially affect web browsing, email clients, document viewers, and other components that rely on WebKit for web content rendering. The vulnerability's presence in both mobile and desktop operating systems creates multiple attack vectors for threat actors, particularly given the widespread use of Apple devices in enterprise and personal environments. Organizations using affected Apple products face significant risk of data breaches, unauthorized access, and potential lateral movement within networks.
Mitigation strategies for CVE-2017-7111 primarily focus on immediate patching and system updates. Apple released security updates for iOS 11, Safari 11, iCloud 7.0, iTunes 12.7, and tvOS 11 to address this vulnerability. Organizations should prioritize applying these updates across all affected Apple devices and applications, particularly in enterprise environments where multiple devices may be in use. Additional protective measures include implementing web filtering solutions, disabling JavaScript in web browsers when not required, and deploying network monitoring tools to detect suspicious web traffic patterns. The vulnerability's classification under the MITRE ATT&CK framework would likely involve techniques such as T1059.007 for script-based attacks and T1203 for exploitation of web applications, making it important for security teams to monitor for these specific attack patterns. Network administrators should also consider implementing sandboxing measures for web browsing applications and regularly reviewing system logs for signs of exploitation attempts.