CVE-2019-8515 in iCloud
Summary
by MITRE
A cross-origin issue existed with the fetch API. This was addressed with improved input validation. This issue is fixed in iOS 12.2, tvOS 12.2, Safari 12.1, iTunes 12.9.4 for Windows, iCloud for Windows 7.11. Processing maliciously crafted web content may disclose sensitive user information.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/08/2023
The vulnerability identified as CVE-2019-8515 represents a cross-origin issue within the fetch API implementation across Apple's ecosystem. This security flaw emerged from inadequate input validation mechanisms that failed to properly restrict cross-origin requests, potentially allowing malicious actors to exploit the API for unauthorized data access. The fetch API, which is fundamental to modern web applications for making network requests, became susceptible to cross-origin resource sharing violations that could compromise user privacy and data integrity. The vulnerability specifically affected Apple's mobile and desktop platforms, including iOS 12.1 and earlier versions, tvOS 12.1 and earlier versions, Safari 12.0 and earlier versions, as well as older iterations of iTunes and iCloud for Windows.
The technical flaw stems from insufficient validation of origin parameters within the fetch API implementation, creating a pathway for attackers to craft malicious web content that could bypass normal cross-origin restrictions. This type of vulnerability aligns with CWE-942, which categorizes overly permissive cross-origin resource sharing policies, and represents a classic example of insufficient input validation that enables unauthorized access patterns. The flaw operates by allowing malicious web pages to make requests to resources on different origins without proper authorization checks, potentially exposing sensitive user information through cross-origin data leakage. Attackers could leverage this vulnerability to access user data that should normally be restricted by browser security policies, particularly when the malicious content is embedded within web pages or applications that utilize the fetch API for network communications.
The operational impact of CVE-2019-8515 extends beyond simple information disclosure, as it represents a fundamental breach in web application security boundaries that could enable more sophisticated attacks. Users of affected Apple platforms faced potential exposure of personal data, session tokens, and other sensitive information when browsing malicious websites or interacting with compromised web content. The vulnerability's presence in widely used applications like Safari and iTunes meant that a broad user base was at risk, particularly since these applications frequently handle sensitive personal information and network communications. Security researchers noted that the flaw could be exploited in conjunction with other attack vectors to create more comprehensive compromise scenarios, making it particularly dangerous in environments where users might encounter malicious content through various digital channels.
Mitigation strategies for CVE-2019-8515 required immediate system updates to address the underlying input validation issues within the fetch API implementation. Apple's release of iOS 12.2, tvOS 12.2, Safari 12.1, iTunes 12.9.4 for Windows, and iCloud for Windows 7.11 included necessary patches that improved validation mechanisms and strengthened cross-origin request handling. Organizations and users should have prioritized updating their systems to these versions to eliminate the vulnerability. The fix implemented by Apple addressed the root cause through enhanced input sanitization and stricter origin validation checks within the fetch API, ensuring that cross-origin requests are properly authenticated and authorized before data access is granted. Security professionals should have monitored for this vulnerability through vulnerability scanning tools and ensured that all affected Apple platform installations were updated to prevent exploitation. This vulnerability serves as a reminder of the critical importance of robust input validation and proper cross-origin resource sharing policies in maintaining web application security.