CVE-2020-9780 in iOS
Summary
by MITRE
The issue was resolved by clearing application previews when content is deleted. This issue is fixed in iOS 13.4 and iPadOS 13.4. A local user may be able to view deleted content in the app switcher.
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Analysis
by VulDB Data Team • 10/06/2020
The vulnerability identified as CVE-2020-9780 represents a critical information disclosure flaw in Apple's iOS and iPadOS operating systems. This security weakness stems from insufficient cleanup procedures when application content is removed from the system, creating a persistent exposure that allows unauthorized access to previously deleted data through the app switcher interface. The flaw specifically affects devices running iOS 13.3 and earlier versions, as well as corresponding iPadOS releases, making it a widespread concern across Apple's mobile ecosystem.
The technical root cause of this vulnerability lies in the improper handling of application preview data during content deletion operations. When users delete content within applications, the system should completely purge all associated preview information from memory and display buffers. However, the flaw allows cached preview data to remain accessible in the app switcher interface, where users can still view deleted content through the application thumbnails and preview windows. This behavior violates fundamental security principles of data sanitization and access control, creating a persistent window of opportunity for unauthorized information exposure.
The operational impact of CVE-2020-9780 extends beyond simple privacy concerns to encompass potential data breaches and information leakage scenarios. A local attacker with physical access to an affected device can exploit this vulnerability to view deleted sensitive information, including personal documents, messages, images, and other application data that should have been permanently removed. This vulnerability particularly affects users who handle confidential information on mobile devices, as the app switcher interface is frequently accessed during normal device usage, increasing the attack surface and potential exposure windows.
Security professionals should note this vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a failure in proper data sanitization procedures. The flaw also corresponds to ATT&CK technique T1552.001, "Unsecured Credentials," as it exposes previously deleted sensitive information through application previews. The vulnerability demonstrates a critical gap in Apple's memory management and data cleanup processes, where the system fails to properly invalidate cached preview information following content deletion operations. This weakness creates a persistent exposure that exists until the device is rebooted or the affected applications are fully closed and reopened.
The remediation for CVE-2020-9780 was implemented through the iOS 13.4 and iPadOS 13.4 updates, which introduced enhanced cleanup procedures for application previews. These updates ensure that when content is deleted from applications, all associated preview data is properly cleared from memory and display buffers, preventing unauthorized access through the app switcher interface. System administrators and security teams should prioritize deployment of these updates across all affected devices, particularly in enterprise environments where sensitive data handling is common. Users should also be educated about the importance of keeping their devices updated to protect against such information disclosure vulnerabilities that could compromise their privacy and data security.