CVE-2021-31008
📋 TL;DR
This is a type confusion vulnerability in Apple's WebKit browser engine that could allow remote code execution when processing malicious web content. It affects Safari and all Apple devices using vulnerable WebKit versions. Attackers could exploit this by tricking users into visiting specially crafted websites.
💻 Affected Systems
- Safari
- 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 →Safari by Apple
Tvos by Apple
Watchos by Apple
⚠️ Risk & Real-World Impact
Worst Case
Full remote code execution with the privileges of the current user, potentially leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Browser compromise leading to session hijacking, credential theft, or installation of malware through drive-by download attacks.
If Mitigated
Limited impact with proper browser sandboxing and security controls, potentially just browser crash or denial of service.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website) but no authentication. Type confusion vulnerabilities often require sophisticated exploitation chains.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Safari 15.1, iOS 15 and iPadOS 15, tvOS 15.1, macOS Monterey 12.0.1, watchOS 8.1
Vendor Advisory: https://support.apple.com/en-us/HT212814
Restart Required: Yes
Instructions:
1. Open System Preferences/Settings on your Apple device. 2. Go to Software Update. 3. Install all available updates. 4. Restart your device when prompted.
🔧 Temporary Workarounds
Disable JavaScript
allDisabling JavaScript in Safari will prevent exploitation but will break most modern websites.
Safari > Preferences > Security > Uncheck 'Enable JavaScript'
Use Alternative Browser
allUse a non-WebKit based browser like Firefox or Chrome until patches are applied.
🧯 If You Can't Patch
- Implement web filtering to block known malicious domains and suspicious JavaScript content.
- Use application whitelisting to prevent unauthorized code execution from browser processes.
🔍 How to Verify
Check if Vulnerable:
Check Safari version: Safari > About Safari. For iOS/iPadOS: Settings > General > About > Version. For macOS: Apple menu > About This Mac > Software Update.Check Version:
macOS: sw_vers -productVersion; iOS: Not available via command line; Safari: defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionStringVerify Fix Applied:
Verify version numbers match or exceed: Safari 15.1, iOS 15, iPadOS 15, tvOS 15.1, macOS Monterey 12.0.1, watchOS 8.1📡 Detection & Monitoring
Log Indicators:
- Safari/WebKit crash logs with memory access violations
- Unexpected browser process spawning child processes
- Browser extensions or plugins loading unexpectedly
Network Indicators:
- Connections to known malicious domains from browser processes
- Unusual outbound traffic patterns from Safari/WebKit processes
SIEM Query:
process_name:"Safari" AND (event_type:"process_creation" OR event_type:"crash") AND parent_process NOT IN ("launchd", "loginwindow")🔗 References
- https://support.apple.com/en-us/HT212814
- https://support.apple.com/en-us/HT212869
- https://support.apple.com/en-us/HT212874
- https://support.apple.com/en-us/HT212875
- https://support.apple.com/en-us/HT212876
- https://support.apple.com/en-us/HT212814
- https://support.apple.com/en-us/HT212869
- https://support.apple.com/en-us/HT212874
- https://support.apple.com/en-us/HT212875
- https://support.apple.com/en-us/HT212876
