CVE-2020-13520
📋 TL;DR
This vulnerability allows remote code execution through a memory corruption flaw in Pixar OpenUSD's file parsing. Attackers can craft malicious USD files that trigger out-of-bounds memory modification when processed. Users and applications that open USD files from untrusted sources are affected.
💻 Affected Systems
- Pixar OpenUSD
- Apple macOS (via USD support)
- Applications using OpenUSD library
📦 What is this software?
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 →Openusd by Pixar
⚠️ Risk & Real-World Impact
Worst Case
Full remote code execution with the privileges of the user/process opening the malicious file, potentially leading to complete system compromise.
Likely Case
Application crash or denial of service, with potential for code execution in targeted attacks.
If Mitigated
Limited to denial of service if memory protections (ASLR, DEP) are effective, or no impact if file is not processed.
🎯 Exploit Status
Proof of concept exists in Talos report. Exploitation requires user interaction to open malicious file but no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: OpenUSD versions after 20.05, Apple security updates 2021-001 and later
Vendor Advisory: https://support.apple.com/kb/HT212011
Restart Required: Yes
Instructions:
1. Update OpenUSD to latest version. 2. For macOS, install Apple security updates. 3. Restart affected applications or system.
🔧 Temporary Workarounds
Restrict USD file processing
allBlock or sandbox processing of USD files from untrusted sources
Application hardening
allRun applications with minimal privileges and enable exploit mitigations
🧯 If You Can't Patch
- Implement strict file validation: only allow USD files from trusted sources
- Use application sandboxing or virtualization to isolate USD file processing
🔍 How to Verify
Check if Vulnerable:
Check OpenUSD version: if 20.05 or earlier, vulnerable. Check macOS security update status.Check Version:
usdcat --version (if available) or check application documentationVerify Fix Applied:
Verify OpenUSD version is >20.05. On macOS, verify security update 2021-001 or later is installed.📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing USD files
- Memory access violation errors
Network Indicators:
- Unexpected downloads of USD files
- File transfers to/from untrusted sources
SIEM Query:
Process:usd* AND (EventID:1000 OR ExceptionCode:c0000005)