CVE-2021-30848
📋 TL;DR
CVE-2021-30848 is a memory corruption vulnerability in Apple's WebKit browser engine that allows remote code execution when processing malicious web content. Attackers can exploit this by tricking users into visiting specially crafted websites. This affects users of vulnerable Apple devices running iOS, iPadOS, or Safari.
💻 Affected Systems
- iOS
- iPadOS
- 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
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the device with full user privileges, allowing data theft, surveillance, and persistence.
Likely Case
Malware installation, credential theft, or device takeover when users visit malicious websites.
If Mitigated
No impact if devices are fully patched or if web content filtering blocks malicious sites.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website) but no authentication. Public proof-of-concept exists in disclosure references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.8, iPadOS 14.8, Safari 15, iOS 15, iPadOS 15
Vendor Advisory: https://support.apple.com/en-us/HT212804
Restart Required: Yes
Instructions:
1. Go to Settings > General > Software Update. 2. Install iOS/iPadOS 14.8 or later. 3. For Safari on macOS, update through System Preferences > Software Update. 4. Restart device after installation.
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily disable JavaScript in Safari to prevent exploitation, though this breaks many websites.
Safari > Preferences > Security > uncheck 'Enable JavaScript'
Use alternative browser
allUse browsers not based on WebKit (Chrome, Firefox) until patched.
🧯 If You Can't Patch
- Implement strict web content filtering to block known malicious sites.
- Use application allowlisting to prevent unauthorized code execution.
🔍 How to Verify
Check if Vulnerable:
Check iOS/iPadOS version in Settings > General > About > Version. If below 14.8 or 15.0, device is vulnerable.Check Version:
On iOS/iPadOS: Settings > General > About > Version. On macOS: Safari > About Safari.Verify Fix Applied:
Verify version shows 14.8 or higher, or 15.0 or higher after update.📡 Detection & Monitoring
Log Indicators:
- Unusual Safari/WebKit process crashes
- Suspicious website visits in browser history
Network Indicators:
- Connections to known malicious domains hosting exploit code
SIEM Query:
source="*browser*" AND (event="crash" OR event="memory_error") AND process="Safari" OR process="WebKit"🔗 References
- http://seclists.org/fulldisclosure/2021/Oct/60
- http://seclists.org/fulldisclosure/2021/Oct/61
- http://www.openwall.com/lists/oss-security/2021/10/26/9
- http://www.openwall.com/lists/oss-security/2021/10/27/1
- http://www.openwall.com/lists/oss-security/2021/10/27/2
- http://www.openwall.com/lists/oss-security/2021/10/27/4
- https://support.apple.com/en-us/HT212807
- https://support.apple.com/en-us/HT212814
- https://support.apple.com/en-us/HT212816
- https://support.apple.com/kb/HT212869
- http://seclists.org/fulldisclosure/2021/Oct/60
- http://seclists.org/fulldisclosure/2021/Oct/61
- http://www.openwall.com/lists/oss-security/2021/10/26/9
- http://www.openwall.com/lists/oss-security/2021/10/27/1
- http://www.openwall.com/lists/oss-security/2021/10/27/2
- http://www.openwall.com/lists/oss-security/2021/10/27/4
- https://support.apple.com/en-us/HT212807
- https://support.apple.com/en-us/HT212814
- https://support.apple.com/en-us/HT212816
- https://support.apple.com/kb/HT212869
