CVE-2021-30802
📋 TL;DR
This is a use-after-free vulnerability in iOS and tvOS WebKit that allows arbitrary code execution when processing malicious web content. Attackers can exploit this by tricking users into visiting specially crafted websites, potentially taking full control of affected devices. All users running vulnerable versions of iOS or tvOS are affected.
💻 Affected Systems
- iOS
- tvOS
📦 What is this software?
Tvos by Apple
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install malware, steal sensitive data, and maintain persistent access to the device.
Likely Case
Attackers deliver malware through malicious websites, potentially stealing credentials, personal data, or enabling further network attacks.
If Mitigated
With proper patching, the vulnerability is eliminated; with web filtering and user education, exploitation attempts are blocked before reaching devices.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website) but no authentication. Use-after-free vulnerabilities in WebKit are commonly exploited in the wild.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.7, tvOS 14.7
Vendor Advisory: https://support.apple.com/en-us/HT212601
Restart Required: Yes
Instructions:
1. Open Settings app. 2. Go to General > Software Update. 3. Install iOS 14.7 or tvOS 14.7 update. 4. Restart device after installation completes.
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily disable JavaScript in Safari to prevent exploitation through web content
Settings > Safari > Advanced > JavaScript > Toggle Off
Use Content Filtering
allDeploy web content filtering to block known malicious websites
🧯 If You Can't Patch
- Implement strict web filtering to block access to untrusted websites
- Educate users about phishing risks and safe browsing practices
🔍 How to Verify
Check if Vulnerable:
Check iOS/tvOS version in Settings > General > About > Version. If version is below 14.7, device is vulnerable.Check Version:
Settings > General > About > Version (iOS/tvOS)Verify Fix Applied:
Verify version shows 14.7 or higher in Settings > General > About > Version.📡 Detection & Monitoring
Log Indicators:
- Unusual Safari/WebKit crashes
- Suspicious website access patterns
- Process memory anomalies
Network Indicators:
- Connections to known malicious domains
- Unusual outbound traffic from iOS/tvOS devices
SIEM Query:
source="ios_logs" AND (event="webkit_crash" OR event="safari_crash") AND version<"14.7"