CVE-2021-30715
📋 TL;DR
This vulnerability in Apple operating systems allows processing a maliciously crafted message to cause a denial of service. It affects users running vulnerable versions of iOS, iPadOS, tvOS, watchOS, and macOS. The issue involves a logic flaw in state management that can be triggered remotely.
💻 Affected Systems
- iOS
- iPadOS
- tvOS
- watchOS
- macOS
📦 What is this software?
Ipados by Apple
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
Complete system crash or freeze requiring reboot, potentially disrupting device functionality and availability.
Likely Case
Application or service crash affecting specific functionality without full system compromise.
If Mitigated
No impact if patched; limited to denial of service without data compromise if unpatched.
🎯 Exploit Status
Requires crafting specific malicious messages but no authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.6, iPadOS 14.6, tvOS 14.6, watchOS 7.5, macOS Big Sur 11.4, Security Update 2021-003 Catalina
Vendor Advisory: https://support.apple.com/en-us/HT212528
Restart Required: Yes
Instructions:
1. Go to Settings > General > Software Update on iOS/iPadOS/watchOS. 2. Go to System Preferences > Software Update on macOS. 3. Install available updates. 4. Restart device after installation.
🔧 Temporary Workarounds
Disable message processing
allLimit exposure to untrusted messages by disabling automatic processing where possible.
🧯 If You Can't Patch
- Segment affected devices from untrusted networks
- Implement application whitelisting to restrict message processing
🔍 How to Verify
Check if Vulnerable:
Check OS version in Settings > General > About (iOS/iPadOS) or About This Mac (macOS).Check Version:
sw_vers (macOS) or Settings > General > About > Version (iOS/iPadOS)Verify Fix Applied:
Confirm OS version matches or exceeds patched versions listed in fix_official.📡 Detection & Monitoring
Log Indicators:
- Unexpected application crashes
- System panic logs
- Message processing errors
Network Indicators:
- Unusual message traffic patterns
- Spike in malformed message attempts
SIEM Query:
search 'application crash' OR 'panic' AND source="apple_device"🔗 References
- https://support.apple.com/en-us/HT212528
- https://support.apple.com/en-us/HT212529
- https://support.apple.com/en-us/HT212530
- https://support.apple.com/en-us/HT212532
- https://support.apple.com/en-us/HT212533
- https://support.apple.com/en-us/HT212528
- https://support.apple.com/en-us/HT212529
- https://support.apple.com/en-us/HT212530
- https://support.apple.com/en-us/HT212532
- https://support.apple.com/en-us/HT212533
