CVE-2021-1753
📋 TL;DR
CVE-2021-1753 is an out-of-bounds read vulnerability in Apple's image processing that could allow arbitrary code execution when processing a malicious image. This affects macOS, iOS, and iPadOS users running vulnerable versions. Attackers could exploit this to gain control of affected devices.
💻 Affected Systems
- macOS
- iOS
- iPadOS
📦 What is this software?
Ipad Os 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 attacker gaining root privileges and persistent access to the device.
Likely Case
Application crash or limited data exposure from memory read, with potential for code execution in targeted attacks.
If Mitigated
No impact if patched; application crash with memory protections enabled.
🎯 Exploit Status
Exploitation requires user interaction to process malicious image. No public exploit code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4, iPadOS 14.4
Vendor Advisory: https://support.apple.com/en-us/HT212146
Restart Required: Yes
Instructions:
1. Open System Preferences > Software Update. 2. Install available updates. 3. Restart device when prompted.
🔧 Temporary Workarounds
Disable automatic image processing
allPrevent automatic loading of images in email clients and web browsers
User education
allTrain users to avoid opening images from untrusted sources
🧯 If You Can't Patch
- Implement application whitelisting to prevent execution of unauthorized code
- Use endpoint protection with memory protection features enabled
🔍 How to Verify
Check if Vulnerable:
Check macOS version with 'sw_vers' command or iOS/iPadOS version in Settings > General > AboutCheck Version:
macOS: sw_vers -productVersion, iOS/iPadOS: Check in Settings > General > AboutVerify Fix Applied:
Verify installed version matches or exceeds patched versions listed in vendor advisory📡 Detection & Monitoring
Log Indicators:
- Application crashes related to image processing
- Memory access violation logs
Network Indicators:
- Unusual image downloads from suspicious sources
SIEM Query:
Image: (process_name contains "Preview" OR process_name contains "Photos") AND (event_type="crash" OR memory_violation="true")