CVE-2020-9960 in watchOS
Summary
by MITRE • 04/03/2021
An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.0.1, tvOS 14.0, macOS Big Sur 11.1, Security Update 2020-001 Catalina, Security Update 2020-007 Mojave, watchOS 7.0, iOS 14.0 and iPadOS 14.0. Processing a maliciously crafted audio file may lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 04/08/2021
The vulnerability identified as CVE-2020-9960 represents a critical out-of-bounds read flaw in Apple's multimedia processing frameworks that affects multiple operating systems including macOS Big Sur, iOS, tvOS, and watchOS. This issue stems from inadequate input validation mechanisms within the audio processing pipeline, where the system fails to properly verify the boundaries of audio data structures before accessing memory locations. The vulnerability manifests when the affected systems process maliciously crafted audio files that contain malformed data structures designed to trigger memory access violations.
The technical nature of this flaw places it firmly within the CWE-125 category of out-of-bounds read vulnerabilities, where an application accesses memory beyond the allocated boundaries of a buffer or data structure. This particular implementation flaw occurs in the audio decoding subsystem where the system does not adequately validate the length and structure of audio file headers before proceeding with data extraction and processing. The vulnerability's classification aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation could enable attackers to execute arbitrary code on compromised systems through carefully constructed audio files.
The operational impact of this vulnerability extends beyond simple data corruption or system instability, as it provides a potential pathway for remote code execution attacks. When an attacker successfully crafts an audio file that triggers the out-of-bounds read condition, the system may experience memory corruption that can be leveraged to execute malicious code with the privileges of the affected application. This poses significant risks in environments where users might encounter malicious audio files through email attachments, web downloads, or media streaming services. The vulnerability affects all affected platforms including iOS 14.0, macOS Big Sur 11.0.1, tvOS 14.0, and watchOS 7.0, making it a widespread concern across Apple's ecosystem.
The exploitation of this vulnerability requires attackers to craft specifically designed audio files that can trigger the memory access violation during normal media processing operations. The fix implemented by Apple addresses this through enhanced input validation mechanisms that properly check audio file structures before processing, ensuring that all memory accesses remain within valid boundaries. System administrators and users should immediately apply the recommended security updates including macOS Big Sur 11.1, Security Update 2020-001 for Catalina, Security Update 2020-007 for Mojave, and corresponding iOS, tvOS, and watchOS updates. Organizations should also implement additional security measures such as network-based file filtering and user education to minimize exposure to potentially malicious audio files. The vulnerability highlights the importance of robust input validation in multimedia processing frameworks and serves as a reminder of the critical security considerations in audio and video handling code within operating systems.