CVE-2021-30979
📋 TL;DR
This CVE describes a buffer overflow vulnerability in Apple's USD file processing that could allow attackers to crash applications or execute arbitrary code. It affects macOS, iOS, and iPadOS users who process malicious USD files. The vulnerability is rated 7.8 CVSS and classified as CWE-120 (buffer copy without checking size).
💻 Affected Systems
- macOS
- iOS
- iPadOS
📦 What is this software?
Ipados by Apple
Macos by Apple
macOS is Apple's desktop and laptop operating system powering Mac computers used by millions of professionals, developers, creative professionals, and enterprise users worldwide. Built on a Unix foundation with the Darwin kernel and modern Cocoa frameworks, macOS delivers a seamless ecosystem integr...
Learn more about Macos →Macos by Apple
macOS is Apple's desktop and laptop operating system powering Mac computers used by millions of professionals, developers, creative professionals, and enterprise users worldwide. Built on a Unix foundation with the Darwin kernel and modern Cocoa frameworks, macOS delivers a seamless ecosystem integr...
Learn more about Macos →⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with system-level privileges, potentially leading to complete system compromise and data exfiltration.
Likely Case
Application crashes (denial of service) when processing malicious USD files, with potential for limited code execution in some scenarios.
If Mitigated
No impact if systems are patched or if USD file processing is restricted to trusted sources.
🎯 Exploit Status
Exploitation requires user interaction to open malicious USD files. No public proof-of-concept has been disclosed, but the vulnerability is documented by ZDI.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Monterey 12.1, iOS 15.2, iPadOS 15.2, macOS Big Sur 11.6.2, Security Update 2021-008 Catalina
Vendor Advisory: https://support.apple.com/en-us/HT212976
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install available updates. 3. Restart the system when prompted. For iOS/iPadOS: Settings > General > Software Update.
🔧 Temporary Workarounds
Restrict USD file processing
allBlock or restrict processing of USD files from untrusted sources
Application sandboxing
macOSUse sandboxed applications for USD file processing to limit potential damage
🧯 If You Can't Patch
- Implement application whitelisting to prevent unauthorized USD file processing applications
- Deploy endpoint detection and response (EDR) solutions to monitor for suspicious USD file processing behavior
🔍 How to Verify
Check if Vulnerable:
Check system version against affected versions. On macOS: About This Mac > Overview. On iOS/iPadOS: Settings > General > About > Version.Check Version:
macOS: sw_vers -productVersion, iOS/iPadOS: Not available via command line (check Settings)Verify Fix Applied:
Verify system version matches or exceeds patched versions listed in fix_official.patch_version📡 Detection & Monitoring
Log Indicators:
- Application crashes related to USD file processing
- Suspicious file opening events for .usd/.usda/.usdc files
Network Indicators:
- Downloads of USD files from untrusted sources
- Unusual outbound connections after USD file processing
SIEM Query:
source="*system.log*" AND ("crash" AND "USD") OR ("Universal Scene Description" AND "exception")🔗 References
- https://support.apple.com/en-us/HT212976
- https://support.apple.com/en-us/HT212978
- https://support.apple.com/en-us/HT212979
- https://support.apple.com/en-us/HT212981
- https://www.zerodayinitiative.com/advisories/ZDI-22-358/
- https://support.apple.com/en-us/HT212976
- https://support.apple.com/en-us/HT212978
- https://support.apple.com/en-us/HT212979
- https://support.apple.com/en-us/HT212981
- https://www.zerodayinitiative.com/advisories/ZDI-22-358/
