CVE-2017-7091 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-2017-7091 represents a critical memory corruption flaw within Apple's WebKit rendering engine that affects multiple operating systems and applications. This weakness resides in the core web browsing component that powers Safari, iOS web views, and various Apple applications, making it particularly dangerous due to its widespread impact across Apple's ecosystem. The vulnerability specifically targets the WebKit component which is responsible for processing and rendering web content, creating a pathway for malicious actors to exploit memory handling mechanisms through specially crafted web pages. The flaw manifests as a memory corruption issue that can be triggered when WebKit processes certain malformed web content, leading to unpredictable behavior and potential system compromise.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions where an attacker can manipulate memory access patterns to execute arbitrary code or cause denial of service. The flaw operates by exploiting improper memory management within WebKit's JavaScript engine and rendering components, allowing remote attackers to craft malicious websites that trigger buffer overflows or use-after-free conditions. When a user visits an attacker-controlled website, the malicious code can manipulate memory pointers and execute shellcode in the context of the vulnerable application. This type of vulnerability is particularly dangerous because it requires no user interaction beyond visiting a malicious website, making it a prime target for drive-by attacks. The exploitation mechanism leverages the inherent complexity of WebKit's architecture where multiple components interact to process web content, creating multiple potential attack vectors.
The operational impact of CVE-2017-7091 extends across Apple's entire product portfolio that utilizes WebKit, including iOS versions prior to 11, Safari browsers, iCloud applications, iTunes software, and tvOS systems. This broad scope creates significant risk for organizations and individual users who may unknowingly encounter malicious web content while browsing the internet. The vulnerability can result in complete system compromise when successfully exploited, allowing attackers to execute arbitrary code with the privileges of the affected application. Additionally, the denial of service component of this vulnerability can cause applications to crash repeatedly, disrupting normal user operations and potentially leading to data loss or system instability. The impact is particularly severe given that these affected products are widely used in enterprise environments where users frequently browse the internet and access web-based applications. The vulnerability's presence in both mobile and desktop operating systems creates a comprehensive attack surface that can be leveraged by threat actors to establish persistent access or conduct large-scale campaigns.
Mitigation strategies for CVE-2017-7091 should prioritize immediate system updates to the latest versions of affected Apple products, as Apple released patches specifically addressing this vulnerability in iOS 11, Safari 11, and corresponding versions of iCloud and iTunes. Organizations should implement network-level protections including web content filtering and sandboxing measures to prevent access to known malicious domains. Security teams should monitor for exploitation attempts through network traffic analysis and endpoint detection systems that can identify anomalous behavior patterns associated with memory corruption attacks. The implementation of web application firewalls and browser hardening measures can provide additional layers of protection, while regular security assessments should be conducted to identify other potential vulnerabilities in the WebKit component. According to ATT&CK framework, this vulnerability maps to T1059.007 for command and scripting interpreter and T1489 for service stop, as exploitation can lead to arbitrary code execution and system disruption. Organizations should also consider implementing user education programs to reduce the risk of social engineering attacks that might leverage this vulnerability through phishing campaigns or malicious links.