CVE-2020-9940 in tvOS
Summary
by MITRE • 10/23/2020
A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 13.6 and iPadOS 13.6, macOS Catalina 10.15.6, tvOS 13.4.8. Processing a maliciously crafted USD file may lead to unexpected application termination or arbitrary code execution.
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Analysis
by VulDB Data Team • 10/04/2022
The vulnerability identified as CVE-2020-9940 represents a critical buffer overflow flaw in Apple's operating systems that affects iOS 13.6 and iPadOS 13.6, macOS Catalina 10.15.6, and tvOS 13.4.8. This issue stems from inadequate memory handling mechanisms when processing Universal Scene Description (USD) files, which are commonly used in 3D graphics applications and content creation workflows. The flaw manifests when applications attempt to parse maliciously crafted USD files, creating conditions where memory boundaries are exceeded during data processing operations.
The technical implementation of this vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and potentially CWE-122 for heap-based buffer overflows depending on the specific memory allocation patterns used by the affected applications. The flaw occurs during the parsing phase of USD file structures where the application fails to properly validate input lengths against allocated buffer sizes. This allows an attacker to craft a specially formatted USD file that, when opened by an affected application, causes memory corruption that can result in either application crash or more severe arbitrary code execution capabilities.
From an operational perspective, this vulnerability presents significant risks to organizations and individual users who may encounter malicious USD files through various attack vectors including email attachments, web downloads, or file sharing platforms. The impact extends beyond simple application instability to potentially enable remote code execution, making it particularly dangerous in enterprise environments where 3D content is frequently shared and processed. The vulnerability affects applications that utilize Pixar's USD framework for 3D content management, including but not limited to Autodesk Maya, Blender, and various Adobe Creative Suite applications that support USD file formats.
The exploitation of this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, where successful exploitation could enable attackers to execute arbitrary code on targeted systems. The attack surface is broad as USD files are commonly used in creative industries, making them attractive attack vectors for threat actors seeking to compromise systems through social engineering or supply chain attacks. Organizations should consider implementing strict file validation policies and sandboxing mechanisms for USD file processing to mitigate potential exploitation risks.
Mitigation strategies should prioritize immediate deployment of the security patches available for iOS 13.6, iPadOS 13.6, macOS Catalina 10.15.6, and tvOS 13.4.8, as these updates contain the necessary memory handling improvements that prevent the buffer overflow conditions. Additional defensive measures include implementing network-based file filtering solutions that can detect and block suspicious USD files, deploying endpoint protection solutions with behavioral monitoring capabilities, and establishing user awareness programs to educate personnel about the risks of opening untrusted 3D content files. Security teams should also consider implementing application whitelisting policies that restrict which applications can process USD files, thereby reducing the attack surface and limiting potential exploitation scenarios.