CVE-2020-3849
📋 TL;DR
CVE-2020-3849 is a critical memory corruption vulnerability in macOS that allows remote attackers to crash applications or execute arbitrary code by exploiting improper input validation. It affects macOS Catalina versions before 10.15.3. All users running vulnerable macOS versions are potentially affected.
💻 Affected Systems
- macOS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with system-level privileges leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Application crashes leading to denial of service, with potential for limited code execution in targeted attacks.
If Mitigated
Minimal impact if patched; unpatched systems remain vulnerable to exploitation attempts.
🎯 Exploit Status
The vulnerability is remotely exploitable without authentication and has been publicly disclosed, making exploitation relatively straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Catalina 10.15.3 or 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 update. 3. Restart the system when prompted.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to vulnerable systems to reduce attack surface
Application Whitelisting
allImplement application control to prevent execution of unauthorized code
🧯 If You Can't Patch
- Isolate vulnerable systems from untrusted networks and internet access
- Implement strict network monitoring and intrusion detection for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check macOS version: if running Catalina version earlier than 10.15.3, system is vulnerable.Check Version:
sw_versVerify Fix Applied:
Verify macOS version is 10.15.3 or later via System Information or terminal command.📡 Detection & Monitoring
Log Indicators:
- Unexpected application crashes, memory access violations, or suspicious process creation
Network Indicators:
- Unusual network connections from macOS systems, especially to suspicious external IPs
SIEM Query:
source="macos" AND (event_type="crash" OR process_name="unexpected")