CVE-2024-40776
📋 TL;DR
A use-after-free vulnerability in Apple's WebKit browser engine allows processing malicious web content to cause unexpected process crashes. This affects users of Safari and Apple devices running vulnerable iOS, iPadOS, watchOS, tvOS, visionOS, and macOS versions. The vulnerability could potentially be leveraged for denial of service or further exploitation.
💻 Affected Systems
- Safari
- iOS
- iPadOS
- watchOS
- tvOS
- visionOS
- macOS
📦 What is this software?
Ipados by Apple
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
Potential remote code execution leading to complete system compromise if combined with other vulnerabilities, though this requires chaining with additional exploits.
Likely Case
Denial of service through browser/application crashes when processing malicious web content.
If Mitigated
Limited to application crashes with no data loss if proper sandboxing and memory protections are in place.
🎯 Exploit Status
Exploitation requires user interaction (visiting malicious website) but no authentication. Use-after-free vulnerabilities typically require precise timing and memory manipulation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 16.7.9, iPadOS 16.7.9, Safari 17.6, iOS 17.6, iPadOS 17.6, watchOS 10.6, tvOS 17.6, visionOS 1.3, macOS Sonoma 14.6
Vendor Advisory: https://support.apple.com/en-us/HT214108
Restart Required: Yes
Instructions:
1. Open Settings app. 2. Go to General > Software Update. 3. Install available updates. 4. Restart device when prompted. For macOS: 1. Open System Settings. 2. Go to General > Software Update. 3. Install available updates. 4. Restart computer.
🔧 Temporary Workarounds
Disable JavaScript
allTemporarily disable JavaScript in Safari to prevent exploitation through malicious web content
Safari > Settings > Security > Uncheck 'Enable JavaScript'
Use Alternative Browser
allUse non-WebKit based browsers (Chrome, Firefox) until patches are applied
🧯 If You Can't Patch
- Implement web content filtering to block known malicious sites
- Use application whitelisting to restrict execution of unauthorized processes
🔍 How to Verify
Check if Vulnerable:
Check current OS/browser version against patched versions listed in affected_systems.versionsCheck Version:
iOS/iPadOS: Settings > General > About > Version; macOS: Apple menu > About This Mac; Safari: Safari menu > About SafariVerify Fix Applied:
Verify OS/browser version matches or exceeds patched versions: iOS/iPadOS 16.7.9+, Safari 17.6+, iOS/iPadOS 17.6+, watchOS 10.6+, tvOS 17.6+, visionOS 1.3+, macOS Sonoma 14.6+📡 Detection & Monitoring
Log Indicators:
- Safari/WebKit process crashes
- Unexpected browser/application terminations
- Memory access violation logs
Network Indicators:
- Connections to known malicious domains serving web content
- Unusual web traffic patterns to suspicious sites
SIEM Query:
source="*" (process_name="Safari" OR process_name="WebKit") AND (event_type="crash" OR error="EXC_BAD_ACCESS" OR error="segmentation fault")🔗 References
- http://seclists.org/fulldisclosure/2024/Jul/15
- http://seclists.org/fulldisclosure/2024/Jul/16
- http://seclists.org/fulldisclosure/2024/Jul/17
- http://seclists.org/fulldisclosure/2024/Jul/18
- http://seclists.org/fulldisclosure/2024/Jul/21
- http://seclists.org/fulldisclosure/2024/Jul/22
- http://seclists.org/fulldisclosure/2024/Jul/23
- https://support.apple.com/en-us/HT214116
- https://support.apple.com/en-us/HT214117
- https://support.apple.com/en-us/HT214119
- https://support.apple.com/en-us/HT214121
- https://support.apple.com/en-us/HT214122
- https://support.apple.com/en-us/HT214123
- https://support.apple.com/en-us/HT214124
- https://www.secpod.com/blog/apple-fixes-multiple-security-vulnerabilities-in-july-2024-updates/
- http://seclists.org/fulldisclosure/2024/Jul/15
- http://seclists.org/fulldisclosure/2024/Jul/16
- http://seclists.org/fulldisclosure/2024/Jul/17
- http://seclists.org/fulldisclosure/2024/Jul/18
- http://seclists.org/fulldisclosure/2024/Jul/21
- http://seclists.org/fulldisclosure/2024/Jul/22
- http://seclists.org/fulldisclosure/2024/Jul/23
- https://lists.debian.org/debian-lts-announce/2024/09/msg00006.html
- https://support.apple.com/en-us/HT214116
- https://support.apple.com/en-us/HT214117
- https://support.apple.com/en-us/HT214119
- https://support.apple.com/en-us/HT214121
- https://support.apple.com/en-us/HT214122
- https://support.apple.com/en-us/HT214123
- https://support.apple.com/en-us/HT214124
- https://support.apple.com/kb/HT214116
- https://support.apple.com/kb/HT214117
- https://support.apple.com/kb/HT214119
- https://support.apple.com/kb/HT214122
- https://support.apple.com/kb/HT214123
- https://support.apple.com/kb/HT214124
