CVE-2020-27941
📋 TL;DR
This macOS kernel vulnerability allows malicious applications to execute arbitrary code with kernel privileges, potentially taking full control of affected systems. It affects macOS Mojave, Catalina, and earlier Big Sur versions before security updates.
💻 Affected Systems
- macOS
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with kernel-level persistence, data theft, and ability to bypass all security controls.
Likely Case
Malicious application gains kernel privileges to install rootkits, intercept sensitive data, or disable security software.
If Mitigated
Limited impact if systems are patched, applications are from trusted sources, and proper endpoint protection is in place.
🎯 Exploit Status
Requires user to execute malicious application. No public exploit code available at disclosure.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Big Sur 11.1, Security Update 2020-001 Catalina, Security Update 2020-007 Mojave
Vendor Advisory: https://support.apple.com/en-us/HT212011
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install available security updates. 3. Restart when prompted.
🔧 Temporary Workarounds
Application Restriction
macOSRestrict application execution to App Store and identified developers only
sudo spctl --master-enable
sudo spctl --enable --label "Mac App Store"
sudo spctl --enable --label "Developer ID"
🧯 If You Can't Patch
- Implement application allowlisting to prevent unauthorized applications from executing
- Deploy endpoint detection and response (EDR) solutions to monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if running Mojave, Catalina, or Big Sur earlier than 11.1, system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version is Big Sur 11.1 or later, or that security updates 2020-001 (Catalina) or 2020-007 (Mojave) are installed.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Unexpected privilege escalation in audit logs
- Suspicious application execution with elevated privileges
Network Indicators:
- Unusual outbound connections from system processes
- DNS requests to suspicious domains from kernel-level processes
SIEM Query:
source="macos" AND (event_type="privilege_escalation" OR process_name="kernel") AND severity="high"