CVE-2020-3845
📋 TL;DR
CVE-2020-3845 is a memory corruption vulnerability in macOS that allows an application to execute arbitrary code with system privileges. This affects macOS Catalina versions before 10.15.3, potentially giving attackers full control of affected systems.
💻 Affected Systems
- macOS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root-level access, allowing installation of persistent malware, data theft, and lateral movement across the network.
Likely Case
Local privilege escalation where a malicious application gains system privileges to bypass security controls and access sensitive data.
If Mitigated
Limited impact if systems are fully patched and application execution is restricted through security policies.
🎯 Exploit Status
Exploitation requires local access or user interaction to run a malicious application. No public exploit code is known, but memory corruption vulnerabilities are often weaponized.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Catalina 10.15.3 and later
Vendor Advisory: https://support.apple.com/HT210919
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install macOS Catalina 10.15.3 or later update. 3. Restart the system when prompted.
🔧 Temporary Workarounds
Restrict application execution
allUse macOS Gatekeeper and application whitelisting to prevent unauthorized applications from running.
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
- Segment vulnerable systems from critical network resources and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if running Catalina version earlier than 10.15.3, the system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version is 10.15.3 or later and check that Security Update 2020-001 is installed.📡 Detection & Monitoring
Log Indicators:
- Unusual process execution with elevated privileges
- Security framework violations
- Application crashes related to memory corruption
Network Indicators:
- Outbound connections from system processes to suspicious destinations
SIEM Query:
process:parent_name="*" AND process:integrity_level="SYSTEM" AND process:command_line CONTAINS suspicious_pattern