CVE-2021-30868
📋 TL;DR
CVE-2021-30868 is a macOS kernel race condition vulnerability that allows malicious applications to execute arbitrary code with kernel privileges. This affects macOS Big Sur and Monterey systems before specific security updates. Attackers could gain complete system control through local application execution.
💻 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 →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 privileges, allowing attackers to install persistent malware, bypass all security controls, and access all user data.
Likely Case
Local privilege escalation where a user-level malicious application gains kernel privileges to bypass security restrictions and install additional payloads.
If Mitigated
Limited impact if systems are fully patched, applications are from trusted sources only, and proper endpoint protection is deployed.
🎯 Exploit Status
Exploitation requires local application execution. Race conditions can be challenging to exploit reliably but have been weaponized in macOS malware.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Big Sur 11.6.1, macOS Monterey 12.0.1
Vendor Advisory: https://support.apple.com/en-us/HT212869
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install available updates. 3. Restart when prompted. 4. Verify update completed successfully.
🔧 Temporary Workarounds
Application Restriction
macOSRestrict application execution to only trusted, signed applications from the App Store or identified developers.
sudo spctl --master-enable
sudo spctl --enable --label "Developer ID"
🧯 If You Can't Patch
- Implement strict application control policies to prevent execution of untrusted applications
- Deploy endpoint detection and response (EDR) solutions with behavioral monitoring for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if running macOS Big Sur before 11.6.1 or macOS Monterey before 12.0.1, system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version is 11.6.1 or higher for Big Sur, or 12.0.1 or higher for Monterey.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- Unexpected privilege escalation in audit logs
- Suspicious process creation with elevated privileges
Network Indicators:
- Unusual outbound connections from system processes
- Command and control traffic from kernel-level processes
SIEM Query:
source="macos" AND (event_type="process_creation" AND parent_process="kernel_task") OR (event_type="privilege_escalation")