CVE-2021-30909
📋 TL;DR
This CVE-2021-30909 is a memory corruption vulnerability in Apple operating systems that allows an application to execute arbitrary code with kernel privileges, potentially leading to full system compromise. It affects multiple Apple devices including iPhones, iPads, Macs, Apple TVs, and Apple Watches running specific vulnerable versions. Users of these devices are at risk if they have not applied the security updates.
💻 Affected Systems
- iOS
- iPadOS
- macOS
- tvOS
- watchOS
📦 What is this software?
Ipad Os 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 →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 →Tvos by Apple
Watchos by Apple
⚠️ Risk & Real-World Impact
Worst Case
An attacker gains full control of the device, allowing them to install malware, steal sensitive data, or use the device as part of a botnet.
Likely Case
Malicious apps could exploit this to bypass security restrictions and perform unauthorized actions, though widespread exploitation is limited by app review processes.
If Mitigated
With proper patching, the risk is eliminated; on unpatched systems, app sandboxing and user permissions may reduce impact but not prevent exploitation.
🎯 Exploit Status
Exploitation requires a malicious application to be installed and executed on the device; no public proof-of-concept has been disclosed, reducing immediate risk.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 15.1, iPadOS 15.1, macOS Monterey 12.0.1, iOS 14.8.1, iPadOS 14.8.1, tvOS 15.1, watchOS 8.1, Security Update 2021-007 Catalina, macOS Big Sur 11.6.1
Vendor Advisory: https://support.apple.com/en-us/HT212867
Restart Required: Yes
Instructions:
1. Go to Settings > General > Software Update on iOS/iPadOS/watchOS/tvOS or System Preferences > Software Update on macOS. 2. Download and install the available update. 3. Restart the device as prompted.
🔧 Temporary Workarounds
Restrict App Installation
allLimit app installations to trusted sources like the App Store to reduce the risk of malicious apps exploiting the vulnerability.
🧯 If You Can't Patch
- Monitor for suspicious app behavior and restrict device usage to essential functions.
- Implement network segmentation to isolate vulnerable devices and reduce potential lateral movement.
🔍 How to Verify
Check if Vulnerable:
Check the device's operating system version against the affected versions listed in the affected_systems section.Check Version:
On iOS/iPadOS: Settings > General > About > Version. On macOS: Apple menu > About This Mac > macOS version. On tvOS: Settings > General > About > Version. On watchOS: Watch app on iPhone > General > About > Version.Verify Fix Applied:
Confirm that the device is running one of the patched versions specified in fix_official.patch_version.📡 Detection & Monitoring
Log Indicators:
- Unusual kernel-level activity or crashes in system logs, unexpected privilege escalation events.
Network Indicators:
- Outbound connections from the device to known malicious IPs or domains post-exploitation.
SIEM Query:
Example: 'event_type:kernel AND action:escalation' or similar based on your SIEM's log sources.🔗 References
- https://support.apple.com/en-us/HT212867
- https://support.apple.com/en-us/HT212868
- https://support.apple.com/en-us/HT212869
- https://support.apple.com/en-us/HT212871
- https://support.apple.com/en-us/HT212872
- https://support.apple.com/en-us/HT212874
- https://support.apple.com/en-us/HT212876
- https://support.apple.com/en-us/HT212867
- https://support.apple.com/en-us/HT212868
- https://support.apple.com/en-us/HT212869
- https://support.apple.com/en-us/HT212871
- https://support.apple.com/en-us/HT212872
- https://support.apple.com/en-us/HT212874
- https://support.apple.com/en-us/HT212876
