CVE-2020-9996
📋 TL;DR
CVE-2020-9996 is a use-after-free vulnerability in Apple operating systems that allows malicious applications to elevate privileges. This affects macOS, iOS, and iPadOS users running vulnerable versions. Successful exploitation could give attackers higher system permissions than intended.
💻 Affected Systems
- macOS
- iOS
- iPadOS
📦 What is this software?
Ipados by Apple
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root-level access, allowing installation of persistent malware, data theft, and lateral movement across networks.
Likely Case
Local privilege escalation enabling attackers to bypass application sandboxes, access protected system resources, and install additional malicious payloads.
If Mitigated
Limited impact with proper application vetting and sandboxing, though still potentially allowing unauthorized access to some system resources.
🎯 Exploit Status
Exploitation requires user interaction to install/run malicious application. Technical details available in public disclosures.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Big Sur 11.0.1, iOS 14.0, iPadOS 14.0
Vendor Advisory: https://support.apple.com/en-us/HT211850
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install available updates for macOS, iOS, or iPadOS. 3. Restart device when prompted.
🔧 Temporary Workarounds
Application Restriction
allRestrict installation of applications from untrusted sources to prevent malicious app execution.
For macOS: System Preferences > Security & Privacy > General > Allow apps downloaded from: App Store
🧯 If You Can't Patch
- Implement strict application allowlisting to prevent unauthorized app execution
- Use endpoint detection and response (EDR) tools to monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check system version: macOS - About This Mac; iOS/iPadOS - Settings > General > AboutCheck Version:
macOS: sw_vers -productVersion; iOS/iPadOS: Settings > General > About > VersionVerify Fix Applied:
Verify system version is macOS 11.0.1+, iOS 14.0+, or iPadOS 14.0+📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege escalation events
- Suspicious process creation with elevated privileges
- Application sandbox violations
Network Indicators:
- Unusual outbound connections from system processes
- Command and control traffic from elevated processes
SIEM Query:
process_creation where parent_process_name contains 'App' and process_integrity_level changed