CVE-2021-30781
📋 TL;DR
CVE-2021-30781 is a local privilege escalation vulnerability in Apple operating systems that allows a local attacker to cause application crashes or execute arbitrary code. This affects users of iOS, macOS, watchOS, and tvOS who haven't updated to the patched versions. The vulnerability requires local access to the device.
💻 Affected Systems
- iOS
- macOS
- watchOS
- tvOS
📦 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 →Tvos by Apple
Watchos by Apple
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with arbitrary code execution at elevated privileges, potentially leading to data theft, persistence, or lateral movement.
Likely Case
Application termination (DoS) or limited code execution in user context, potentially enabling privilege escalation.
If Mitigated
No impact if patched; limited impact if proper application sandboxing and least privilege controls are enforced.
🎯 Exploit Status
Apple addressed this with 'improved checks' suggesting input validation or bounds checking issues. Requires local access but no specific authentication mentioned.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-005 Mojave, Security Update 2021-004 Catalina
Vendor Advisory: https://support.apple.com/en-us/HT212600
Restart Required: Yes
Instructions:
1. Open Settings/System Preferences. 2. Navigate to Software Update. 3. Download and install the latest update. 4. Restart the device when prompted.
🧯 If You Can't Patch
- Restrict physical access to devices
- Implement strict application control policies to limit unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check system version against affected versions: iOS < 14.7, macOS < 11.5, watchOS < 7.6, tvOS < 14.7, or check if Mojave/Catalina security updates are missing.Check Version:
iOS/tvOS: Settings > General > About > Version; macOS: Apple menu > About This Mac; watchOS: Watch app > General > AboutVerify Fix Applied:
Verify system version matches or exceeds patched versions: iOS ≥ 14.7, macOS ≥ 11.5, watchOS ≥ 7.6, tvOS ≥ 14.7, or confirm Security Update 2021-005/004 is installed.📡 Detection & Monitoring
Log Indicators:
- Unexpected application crashes
- Process creation from unusual locations
- Privilege escalation attempts
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
Search for: 'process crash' OR 'segmentation fault' OR 'privilege escalation' on Apple devices with unpatched versions🔗 References
- https://support.apple.com/en-us/HT212600
- https://support.apple.com/en-us/HT212601
- https://support.apple.com/en-us/HT212602
- https://support.apple.com/en-us/HT212603
- https://support.apple.com/en-us/HT212604
- https://support.apple.com/en-us/HT212605
- https://support.apple.com/en-us/HT212600
- https://support.apple.com/en-us/HT212601
- https://support.apple.com/en-us/HT212602
- https://support.apple.com/en-us/HT212603
- https://support.apple.com/en-us/HT212604
- https://support.apple.com/en-us/HT212605
