CVE-2020-9796
📋 TL;DR
This macOS kernel vulnerability allows a malicious application to exploit a race condition to execute arbitrary code with kernel privileges. It affects macOS systems before version 10.15.5. Attackers could gain complete control of affected systems.
💻 Affected Systems
- macOS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with kernel-level persistence, data theft, and installation of rootkits or backdoors.
Likely Case
Local privilege escalation allowing malware to bypass security controls and maintain persistence.
If Mitigated
Limited impact if systems are patched and application execution is restricted to trusted sources.
🎯 Exploit Status
Race condition exploitation requires precise timing and local access. No public exploits known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Catalina 10.15.5 or later
Vendor Advisory: https://support.apple.com/kb/HT211170
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install macOS Catalina 10.15.5 update. 3. Restart when prompted.
🔧 Temporary Workarounds
Restrict application execution
allOnly allow execution of signed applications from identified developers or App Store
sudo spctl --master-enable
sudo spctl --enable --label "Developer ID"
🧯 If You Can't Patch
- Implement strict application control policies to prevent untrusted applications from executing
- Monitor for suspicious process behavior and privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if below 10.15.5, system is vulnerableCheck Version:
sw_versVerify Fix Applied:
Verify macOS version is 10.15.5 or higher📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Unexpected privilege escalation in process monitoring
- Suspicious kernel module loading
Network Indicators:
- None - local exploitation only
SIEM Query:
process where parent_process_name != "launchd" and integrity_level changed