CVE-2020-3887 in iCloud
Summary
by MITRE
A logic issue was addressed with improved restrictions. This issue is fixed in iOS 13.4 and iPadOS 13.4, tvOS 13.4, Safari 13.1, iTunes for Windows 12.10.5, iCloud for Windows 10.9.3, iCloud for Windows 7.18. A download's origin may be incorrectly associated.
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Analysis
by VulDB Data Team • 10/06/2020
The vulnerability identified as CVE-2020-3887 represents a logic flaw in Apple's software ecosystem that affects multiple platforms including iOS, iPadOS, tvOS, and various desktop applications. This issue stems from inadequate validation mechanisms that allow for incorrect association of download origins, creating potential security risks for users who may unknowingly execute malicious code or access unauthorized resources. The vulnerability specifically impacts the way software handles and verifies download sources, potentially enabling attackers to manipulate the system's trust model and compromise user security.
The technical implementation of this flaw involves improper validation of download origins within Apple's software distribution frameworks. When users download content from various sources, the system should maintain strict associations between the download source and the actual origin of the file. However, the logic error allows for scenarios where downloads may be incorrectly attributed to different origins than their actual source, potentially bypassing security checks and validation mechanisms. This type of vulnerability falls under the category of improper input validation and can be classified as a CWE-252 weakness related to improper validation of input. The flaw essentially creates a trust boundary violation where the system cannot reliably verify the authenticity of downloaded content based on its source.
The operational impact of CVE-2020-3887 extends across multiple Apple platforms and applications, including Safari web browser, iTunes, and iCloud synchronization tools. Users may experience situations where malicious downloads appear to originate from trusted sources, potentially leading to successful phishing attacks, malware distribution, or unauthorized access to sensitive data. The vulnerability particularly affects users who rely on these applications for file downloads and synchronization, as the incorrect origin association could enable attackers to exploit user trust in legitimate software sources. This issue demonstrates how seemingly minor logic flaws can create significant security implications, especially when they affect core system functions that users interact with regularly. The vulnerability may also align with ATT&CK technique T1195.001 related to "Phishing: Spearphishing Attachment" where attackers could exploit the incorrect download origin associations to deliver malicious payloads.
The remediation for this vulnerability required updates across multiple Apple platforms, with iOS 13.4, iPadOS 13.4, and tvOS 13.4 receiving the necessary patches. Additionally, Safari 13.1, iTunes for Windows 12.10.5, and iCloud for Windows versions 10.9.3 and 7.18 were updated to address the issue. These updates implemented improved restriction mechanisms that properly validate download origins and maintain accurate associations between downloads and their actual sources. The fix likely involved strengthening the input validation processes and implementing more robust source verification mechanisms within the software's download handling components. Organizations should prioritize deployment of these updates to ensure complete protection against potential exploitation of this logic flaw, as the vulnerability could be leveraged in targeted attacks against users who frequently download content from various sources through Apple's ecosystem. The resolution addresses the root cause by ensuring that download origin associations are properly maintained and validated throughout the software's operation cycle.