CVE-2017-7090 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 bypass the Same Origin Policy and obtain sensitive cookie information via a custom URL scheme.
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Analysis
by VulDB Data Team • 01/20/2021
The vulnerability identified as CVE-2017-7090 represents a critical security flaw within Apple's WebKit rendering engine that affected multiple Apple operating systems and applications. This issue specifically targets the Same Origin Policy implementation within WebKit, which serves as the core component responsible for web content rendering across Apple's ecosystem including iOS, macOS, tvOS, and various desktop applications. The vulnerability exists in versions of iOS prior to 11, Safari prior to version 11, iCloud for Windows before version 7.0, iTunes for Windows before version 12.7, and tvOS prior to version 11, creating a widespread impact across Apple's software portfolio.
The technical flaw stems from improper handling of custom URL schemes within the WebKit component, which allows malicious actors to exploit the browser's security boundaries. When a specially crafted web page is loaded, the vulnerability enables attackers to bypass the fundamental Same Origin Policy that normally prevents web pages from accessing resources from different domains or origins. This weakness specifically manifests when custom URL schemes are processed, allowing remote attackers to manipulate the browser's security context and gain unauthorized access to sensitive cookie information that should normally be restricted to specific origins. The exploitation occurs through carefully constructed URLs that leverage the WebKit component's insufficient validation of scheme handling.
The operational impact of this vulnerability is severe as it provides attackers with the capability to perform cross-site scripting attacks and cookie theft without user interaction. An attacker could craft malicious web content that, when loaded in a victim's browser, would allow unauthorized access to authentication cookies and session data from other origins. This could lead to session hijacking, account takeover, and unauthorized access to sensitive information. The vulnerability is particularly dangerous because it affects multiple platforms simultaneously, increasing the attack surface and the potential for successful exploitation across different Apple products and operating systems.
Security researchers have classified this vulnerability under CWE-284, which relates to improper access control, and it aligns with ATT&CK technique T1071.001 for application layer protocol usage. The flaw represents a significant bypass of web security mechanisms that are fundamental to preventing cross-site attacks. Organizations and users should immediately update to the patched versions of affected Apple software, as the vulnerability allows for remote code execution through cookie manipulation. The mitigation strategy involves applying the latest security patches from Apple, which address the WebKit component's handling of custom URL schemes and restore proper Same Origin Policy enforcement. Additionally, network administrators should monitor for suspicious web traffic patterns and consider implementing additional security measures such as web application firewalls to protect against exploitation attempts targeting this vulnerability.