CVE-2021-30991
📋 TL;DR
This vulnerability allows a malicious application to execute arbitrary code with kernel privileges on iOS/iPadOS devices. An out-of-bounds read in the kernel could be exploited to gain full system control. Only iOS/iPadOS devices running versions before 15.2 are affected.
💻 Affected Systems
- iPhone
- iPad
📦 What is this software?
Ipados by Apple
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise with kernel-level persistence, data theft, and ability to bypass all security controls.
Likely Case
Malicious app gains root privileges, installs persistent malware, and accesses sensitive user data.
If Mitigated
Limited impact if device is already patched or if app sandboxing prevents initial access.
🎯 Exploit Status
Requires user to install malicious application; kernel exploitation requires sophisticated techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 15.2, iPadOS 15.2
Vendor Advisory: https://support.apple.com/en-us/HT212976
Restart Required: Yes
Instructions:
1. Open Settings app. 2. Tap General. 3. Tap Software Update. 4. Download and install iOS/iPadOS 15.2 or later. 5. Restart device when prompted.
🔧 Temporary Workarounds
Restrict App Installation
allOnly allow app installation from App Store and trusted developers
Settings > General > Device Management > Verify trusted developers
🧯 If You Can't Patch
- Restrict device to enterprise app store only
- Implement mobile device management (MDM) to monitor for suspicious app installations
🔍 How to Verify
Check if Vulnerable:
Check iOS/iPadOS version in Settings > General > About > Software VersionCheck Version:
Not applicable for iOS devices (use Settings app)Verify Fix Applied:
Verify version is 15.2 or higher in Settings > General > About > Software Version📡 Detection & Monitoring
Log Indicators:
- MDM logs showing unauthorized app installations
- Crash reports from kernel processes
Network Indicators:
- Unusual outbound connections from iOS devices
- Traffic to known malicious domains
SIEM Query:
device.os.name:"iOS" AND device.os.version:"<15.2" AND event.action:"app_install"