CVE-2021-1874
📋 TL;DR
CVE-2021-1874 is a privilege escalation vulnerability in iOS and iPadOS that allows malicious applications to execute arbitrary code with kernel privileges. This affects all iOS/iPadOS devices running versions before 14.5. Attackers could gain complete control over affected devices.
💻 Affected Systems
- iPhone
- iPad
- iPod touch
📦 What is this software?
Ipados by Apple
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing installation of persistent malware, data theft, surveillance capabilities, and bypassing all security controls.
Likely Case
Targeted attacks against high-value individuals or organizations to install spyware, steal credentials, or establish footholds in corporate networks.
If Mitigated
Limited impact if devices are fully patched and app installation is restricted to App Store only.
🎯 Exploit Status
Requires user to install malicious application, but Apple's security research indicates this was actively exploited in the wild.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: iOS 14.5 and iPadOS 14.5
Vendor Advisory: https://support.apple.com/en-us/HT212317
Restart Required: Yes
Instructions:
1. Go to Settings > General > Software Update. 2. Download and install iOS 14.5 or later. 3. Restart device when prompted.
🔧 Temporary Workarounds
Restrict App Installation
iosLimit app installation to App Store only to prevent installation of malicious applications.
Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Installing Apps > Don't Allow
🧯 If You Can't Patch
- Isolate vulnerable devices from critical networks and sensitive data
- Implement strict mobile device management (MDM) policies to monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check iOS version in Settings > General > About > Version. If version is below 14.5, device is vulnerable.Check Version:
Settings > General > About > VersionVerify Fix Applied:
Verify iOS version is 14.5 or higher in Settings > General > About > Version.📡 Detection & Monitoring
Log Indicators:
- Unusual kernel process creation
- Suspicious app installation outside App Store
- Unexpected privilege escalation events
Network Indicators:
- Unusual outbound connections from iOS devices
- Communication with known malicious domains
SIEM Query:
source="ios_device" AND (event_type="privilege_escalation" OR app_installation_source!="app_store")