CVE-2021-1870
📋 TL;DR
CVE-2021-1870 is a critical logic vulnerability in Apple operating systems that allows remote attackers to execute arbitrary code on affected devices. This affects macOS, iOS, and iPadOS systems running outdated versions. Apple has confirmed this vulnerability was actively exploited in the wild before patches were released.
💻 Affected Systems
- macOS
- iOS
- iPadOS
📦 What is this software?
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Fedora by Fedoraproject
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...
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⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the device, enabling data theft, persistence, and lateral movement.
Likely Case
Remote code execution leading to malware installation, credential theft, or device takeover for botnet participation.
If Mitigated
Limited impact with proper network segmentation and endpoint protection detecting exploitation attempts.
🎯 Exploit Status
Apple confirmed active exploitation in the wild. The vulnerability allows remote code execution without authentication.
🛠️ 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. For enterprise: Deploy updates via MDM or Apple Business/School Manager.
🔧 Temporary Workarounds
Network Segmentation
allIsolate vulnerable devices from internet and untrusted networks
Application Whitelisting
allRestrict execution of unauthorized applications
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable devices
- Deploy endpoint detection and response (EDR) solutions with behavioral monitoring
🔍 How to Verify
Check if Vulnerable:
Check OS version: macOS: About This Mac > Overview; iOS/iPadOS: Settings > General > About > VersionCheck Version:
macOS: sw_vers -productVersion; iOS/iPadOS: Not available via command line on non-jailbroken devicesVerify Fix Applied:
Verify version is equal to or newer than: macOS 11.2+, iOS 14.4+, iPadOS 14.4+📡 Detection & Monitoring
Log Indicators:
- Unexpected process execution
- System integrity violations
- Network connections to suspicious IPs
Network Indicators:
- Unusual outbound connections from Apple devices
- Traffic patterns matching known exploit signatures
SIEM Query:
source="apple-device-logs" AND (event_type="process_execution" AND process_name NOT IN allowed_processes) OR (event_type="network_connection" AND dest_ip IN threat_intel_feeds)🔗 References
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
- https://security.gentoo.org/glsa/202104-03
- https://support.apple.com/en-us/HT212146
- https://support.apple.com/en-us/HT212147
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
- https://security.gentoo.org/glsa/202104-03
- https://support.apple.com/en-us/HT212146
- https://support.apple.com/en-us/HT212147
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1870
