CVE-2021-30818
📋 TL;DR
CVE-2021-30818 is a type confusion vulnerability in Apple's WebKit browser engine that allows arbitrary code execution when processing malicious web content. This affects users of Apple devices running vulnerable iOS, iPadOS, tvOS, watchOS, and Safari versions. Attackers can exploit this by tricking users into visiting malicious websites.
💻 Affected Systems
- iOS
- iPadOS
- tvOS
- watchOS
- Safari
📦 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
Complete compromise of affected device with attacker gaining full control, data theft, and persistence.
Likely Case
Drive-by compromise when users visit malicious websites, leading to malware installation and data exfiltration.
If Mitigated
No impact if devices are fully patched and users avoid untrusted websites.
🎯 Exploit Status
Exploitation requires user to visit malicious website but no authentication needed. Public exploit details exist in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.8, iPadOS 14.8, tvOS 15, iOS 15, iPadOS 15, Safari 15, watchOS 8
Vendor Advisory: https://support.apple.com/en-us/HT212807
Restart Required: Yes
Instructions:
1. Go to Settings > General > Software Update on iOS/iPadOS/watchOS. 2. Install available updates. 3. For macOS, update Safari via System Preferences > Software Update. 4. Restart device after installation.
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily disable JavaScript in Safari to prevent exploitation via web content.
Safari > Preferences > Security > uncheck 'Enable JavaScript'
Use Alternative Browser
allUse browsers not based on WebKit engine until patches are applied.
🧯 If You Can't Patch
- Restrict web browsing to trusted sites only using content filtering or web proxies.
- Implement network segmentation to isolate vulnerable devices from critical systems.
🔍 How to Verify
Check if Vulnerable:
Check device version in Settings > General > About > Version. If version is below patched versions listed, device is vulnerable.Check Version:
iOS/iPadOS/watchOS: Settings > General > About > Version. macOS: Safari > About Safari.Verify Fix Applied:
Confirm device version matches or exceeds patched versions: iOS 14.8+, iPadOS 14.8+, tvOS 15+, iOS 15+, iPadOS 15+, Safari 15+, watchOS 8+.📡 Detection & Monitoring
Log Indicators:
- Unusual Safari/WebKit process crashes
- Suspicious JavaScript execution patterns in web logs
Network Indicators:
- Connections to known malicious domains serving exploit code
- Unusual outbound traffic from Apple devices
SIEM Query:
source="*web*" AND (process="Safari" OR process="WebKit") AND event="crash"🔗 References
- http://www.openwall.com/lists/oss-security/2021/12/20/6
- https://support.apple.com/en-us/HT212807
- https://support.apple.com/en-us/HT212814
- https://support.apple.com/en-us/HT212815
- https://support.apple.com/en-us/HT212816
- https://support.apple.com/en-us/HT212819
- https://support.apple.com/kb/HT212869
- http://www.openwall.com/lists/oss-security/2021/12/20/6
- https://support.apple.com/en-us/HT212807
- https://support.apple.com/en-us/HT212814
- https://support.apple.com/en-us/HT212815
- https://support.apple.com/en-us/HT212816
- https://support.apple.com/en-us/HT212819
- https://support.apple.com/kb/HT212869
