CVE-2021-1763
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code or crash applications by tricking users into opening malicious USD (Universal Scene Description) files. It affects macOS, iOS, and iPadOS users who process USD files. The buffer overflow occurs due to insufficient bounds checking in USD file processing.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the user opening the malicious USD file, potentially leading to full system compromise.
Likely Case
Application crashes (denial of service) when processing specially crafted USD files, disrupting workflow.
If Mitigated
No impact if systems are patched or if USD file processing is disabled/restricted.
🎯 Exploit Status
Exploitation requires user interaction to open a malicious USD file; no authentication needed but social engineering may be involved.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4, iPadOS 14.4
Vendor Advisory: https://support.apple.com/en-us/HT212146
Restart Required: Yes
Instructions:
1. Go to System Preferences > Software Update. 2. Install the latest security update for your macOS/iOS/iPadOS version. 3. Restart the device after installation.
🔧 Temporary Workarounds
Disable USD file processing
allPrevent applications from opening USD files by adjusting file associations or using application controls.
🧯 If You Can't Patch
- Restrict user permissions to limit impact of potential code execution.
- Use application whitelisting to block untrusted USD file handlers.
🔍 How to Verify
Check if Vulnerable:
Check the macOS/iOS/iPadOS version in System Preferences > About This Mac or Settings > General > About.Check Version:
sw_vers (macOS) or check Settings > General > About (iOS/iPadOS)Verify Fix Applied:
Verify the version matches or exceeds the patched versions listed in the fix_official section.📡 Detection & Monitoring
Log Indicators:
- Application crashes related to USD file processing
- Unexpected process executions after opening USD files
Network Indicators:
- Downloads of USD files from untrusted sources
- Network traffic patterns indicative of exploitation
SIEM Query:
Search for events where USD files are opened followed by abnormal process activity or crashes.