CVE-2021-30799
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code on affected Apple devices by tricking users into visiting malicious web content. It affects iOS, macOS Catalina, and macOS Mojave users who haven't updated to the patched versions. The memory corruption issues could be exploited through crafted web content.
💻 Affected Systems
- iOS
- macOS
📦 What is this software?
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 →⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining complete control over the device, allowing data theft, persistence installation, and lateral movement.
Likely Case
Malicious website executes code on user's device, potentially stealing credentials, personal data, or installing malware.
If Mitigated
Attack fails due to updated software or security controls blocking malicious web content.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website) but no authentication. Apple typically doesn't disclose exploit details until patches are widely deployed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.7, macOS Big Sur 11.5, Security Update 2021-004 Catalina, Security Update 2021-005 Mojave
Vendor Advisory: https://support.apple.com/en-us/HT212600
Restart Required: Yes
Instructions:
1. Open Settings/System Preferences. 2. Go to Software Update. 3. Install available updates. 4. Restart device when prompted.
🔧 Temporary Workarounds
Disable JavaScript
macosTemporarily disable JavaScript in Safari to prevent exploitation through web content.
Safari > Preferences > Security > uncheck 'Enable JavaScript'
Use alternative browser
allUse non-WebKit browsers like Firefox or Chrome until patched.
🧯 If You Can't Patch
- Restrict web browsing to trusted sites only using content filtering
- Implement application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check iOS version in Settings > General > About > Version. Check macOS version in Apple menu > About This Mac.Check Version:
sw_vers (macOS) or Settings app (iOS)Verify Fix Applied:
Verify version is iOS 14.7 or later, macOS Big Sur 11.5 or later, or appropriate security updates installed for Catalina/Mojave.📡 Detection & Monitoring
Log Indicators:
- Unusual process spawning from Safari/WebKit processes
- Memory access violations in system logs
Network Indicators:
- Connections to suspicious domains from Safari/WebKit processes
- Unusual outbound traffic patterns
SIEM Query:
process_name:Safari AND (event_id:4688 OR parent_process_name:WebKit) AND command_line CONTAINS suspicious_pattern🔗 References
- https://support.apple.com/en-us/HT212600
- https://support.apple.com/en-us/HT212601
- https://support.apple.com/en-us/HT212602
- https://support.apple.com/en-us/HT212603
- https://support.apple.com/en-us/HT212600
- https://support.apple.com/en-us/HT212601
- https://support.apple.com/en-us/HT212602
- https://support.apple.com/en-us/HT212603
