CVE-2021-30701
📋 TL;DR
This vulnerability allows arbitrary code execution by processing a maliciously crafted image on Apple devices. It affects users running vulnerable versions of iOS, iPadOS, tvOS, watchOS, and macOS who open malicious image files.
💻 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 compromise leading to data theft, ransomware deployment, or persistent backdoor installation
Likely Case
Malware installation through phishing emails or malicious websites containing crafted images
If Mitigated
Limited impact with proper patch management and user education about opening untrusted files
🎯 Exploit Status
Exploitation requires user interaction to open a malicious image file. No public exploit code is known, but the vulnerability is remotely exploitable via web content or email attachments.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: tvOS 14.6, iOS 14.6, iPadOS 14.6, Security Update 2021-003 Catalina, macOS Big Sur 11.4, watchOS 7.5
Vendor Advisory: https://support.apple.com/en-us/HT212528
Restart Required: Yes
Instructions:
1. Open Settings app. 2. Go to General > Software Update. 3. Install the latest available update. 4. Restart device when prompted.
🔧 Temporary Workarounds
Disable automatic image loading
allConfigure email clients and web browsers to not automatically load images from untrusted sources
User education
allTrain users to avoid opening image files from unknown or untrusted sources
🧯 If You Can't Patch
- Implement application whitelisting to prevent execution of unauthorized applications
- Deploy network filtering to block known malicious image file downloads
🔍 How to Verify
Check if Vulnerable:
Check current OS version against affected versions list. On iOS/iPadOS: Settings > General > About > Version. On macOS: Apple menu > About This Mac > Overview.Check Version:
On macOS: sw_vers -productVersion. On iOS/iPadOS: UIDevice.current.systemVersion (programmatic)Verify Fix Applied:
Verify OS version is equal to or greater than the patched versions listed in the fix section📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing image files
- Unexpected process execution following image file access
Network Indicators:
- Downloads of image files from suspicious sources followed by unusual outbound connections
SIEM Query:
source="apple_system_logs" AND (event="crash" AND process="*image*" OR event="process_execution" AND parent_process="*image*")🔗 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
