CVE-2020-3851
📋 TL;DR
CVE-2020-3851 is a use-after-free vulnerability in macOS that allows an application to gain elevated privileges. This affects macOS High Sierra, Mojave, and Catalina systems. Successful exploitation could lead to privilege escalation attacks.
💻 Affected Systems
- macOS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An attacker gains root privileges on the system, enabling complete system compromise, data theft, and persistent backdoor installation.
Likely Case
Local privilege escalation allowing malware or malicious users to bypass security restrictions and execute code with higher privileges.
If Mitigated
With proper patch management and least privilege principles, impact is limited to isolated incidents with minimal lateral movement.
🎯 Exploit Status
Exploitation requires local access or ability to run code on the target system. No public exploit code is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Catalina 10.15.4, Security Update 2020-002 Mojave, Security Update 2020-002 High Sierra
Vendor Advisory: https://support.apple.com/en-us/HT210919
Restart Required: Yes
Instructions:
1. Open System Preferences 2. Click Software Update 3. Install available security updates 4. Restart when prompted
🔧 Temporary Workarounds
Restrict application execution
macOSLimit execution of untrusted applications through application whitelisting or Gatekeeper settings
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 code
- Enforce least privilege principles and limit user administrative access
🔍 How to Verify
Check if Vulnerable:
Check macOS version in System Preferences > About This MacCheck Version:
sw_versVerify Fix Applied:
Verify macOS version is 10.15.4 or later for Catalina, or confirm security updates 2020-002 are installed for Mojave/High Sierra📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation events in system logs
- Suspicious process creation with elevated privileges
Network Indicators:
- Not applicable - local exploitation vulnerability
SIEM Query:
source="macos_system_logs" AND (event="privilege_escalation" OR process_elevation="true")