CVE-2021-1829
📋 TL;DR
CVE-2021-1829 is a type confusion vulnerability in macOS that allows an application to execute arbitrary code with kernel privileges. This affects macOS Big Sur versions prior to 11.3, enabling complete system compromise.
💻 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
Full system takeover with kernel-level privileges, allowing attackers to install persistent malware, steal all data, and control the entire system.
Likely Case
Malicious applications exploiting this to gain root access, install backdoors, or bypass security controls.
If Mitigated
Limited impact if systems are isolated, have strict application controls, and minimal user privileges.
🎯 Exploit Status
Requires local application execution. Type confusion vulnerabilities are often exploited through crafted inputs to kernel interfaces.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Big Sur 11.3
Vendor Advisory: https://support.apple.com/en-us/HT212325
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install macOS Big Sur 11.3 update. 3. Restart the system when prompted.
🔧 Temporary Workarounds
Restrict application execution
allLimit execution of untrusted applications through macOS Gatekeeper and application whitelisting
sudo spctl --master-enable
sudo spctl --enable
🧯 If You Can't Patch
- Isolate affected systems from network access and sensitive data
- Implement strict application control policies to prevent execution of untrusted software
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if running Big Sur version earlier than 11.3, system is vulnerableCheck Version:
sw_versVerify Fix Applied:
Verify macOS version is 11.3 or later and check Apple security updates are applied📡 Detection & Monitoring
Log Indicators:
- Unexpected kernel extensions loading
- Privilege escalation attempts in system logs
- Unusual 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_system_logs" AND (event_type="privilege_escalation" OR process_name="kernel")