CVE-2021-30792
📋 TL;DR
This vulnerability allows arbitrary code execution through malicious image processing. An attacker can craft a malicious image that triggers an out-of-bounds write when processed by affected Apple systems, potentially leading to full system compromise. Affects iOS and macOS users running vulnerable versions.
💻 Affected Systems
- iOS
- macOS
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with kernel-level privileges, allowing complete control over the device, data theft, and persistence.
Likely Case
Arbitrary code execution with user privileges, enabling data access, surveillance, and further system exploitation.
If Mitigated
Limited impact with proper network segmentation and application sandboxing, potentially preventing lateral movement.
🎯 Exploit Status
Requires user to process a malicious image. No public exploit code available as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.7, macOS Big Sur 11.5
Vendor Advisory: https://support.apple.com/en-us/HT212601
Restart Required: Yes
Instructions:
1. Open Settings app. 2. Go to General > Software Update. 3. Download and install iOS 14.7/macOS 11.5. 4. Restart device when prompted.
🔧 Temporary Workarounds
Disable automatic image processing
allPrevent automatic image loading in email clients and web browsers
User education
allTrain users to avoid opening images from untrusted sources
🧯 If You Can't Patch
- Implement application sandboxing to limit potential damage
- Use network segmentation to isolate vulnerable systems
🔍 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:
iOS: Settings > General > About > Version. macOS: sw_vers -productVersionVerify Fix Applied:
Verify version is iOS 14.7 or later, or macOS 11.5 or later.📡 Detection & Monitoring
Log Indicators:
- Crash reports from image processing services
- Unexpected process execution following image file access
Network Indicators:
- Unusual outbound connections after image processing
- Download of suspicious image files
SIEM Query:
Process creation events following image file access OR crash logs containing image processing components🔗 References
- https://support.apple.com/en-us/HT212601
- https://support.apple.com/en-us/HT212602
- https://support.apple.com/kb/HT212600
- https://support.apple.com/kb/HT212603
- https://support.apple.com/en-us/HT212601
- https://support.apple.com/en-us/HT212602
- https://support.apple.com/kb/HT212600
- https://support.apple.com/kb/HT212603
