CVE-2020-3837 – This is a memory corruption vulnerability in Ap... (How to Fix)

Q: What is the severity of CVE-2020-3837?

CVE-2020-3837 has a CVSS score of 7.8 (HIGH). This is a memory corruption vulnerability in Apple operating systems that allows an application to execute arbitrary code with kernel privileges. It affects iOS, iPadOS, macOS, tvOS, and watchOS. Attackers could gain complete control over affected devices.

📋 TL;DR

This is a memory corruption vulnerability in Apple operating systems that allows an application to execute arbitrary code with kernel privileges. It affects iOS, iPadOS, macOS, tvOS, and watchOS. Attackers could gain complete control over affected devices.

💻 Affected Systems

Products:

iOS
iPadOS
macOS
tvOS
watchOS

Versions: Versions prior to iOS 13.3.1, iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2

Operating Systems: iOS, iPadOS, macOS, tvOS, watchOS

Default Config Vulnerable: ⚠️ Yes

Notes: All devices running affected versions are vulnerable by default. No special configuration required.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Full device compromise with kernel-level privileges, allowing installation of persistent malware, data theft, and complete system control.

🟠

Likely Case

Targeted attacks against high-value individuals or organizations to install spyware or ransomware.

🟢

If Mitigated

Limited impact if devices are fully patched and have security controls like app sandboxing and code signing enforcement.

🌐 Internet-Facing: MEDIUM

🏢 Internal Only: HIGH

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires a malicious application to be installed on the device. No public exploit code is known.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: iOS 13.3.1, iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2

Vendor Advisory: https://support.apple.com/HT210918

Restart Required: Yes

Instructions:

1. Go to Settings > General > Software Update on iOS/iPadOS/watchOS. 2. For macOS, go to System Preferences > Software Update. 3. For tvOS, go to Settings > System > Software Updates. 4. Download and install the latest update. 5. Restart the device after installation.

🔧 Temporary Workarounds

Application Restriction

all

Restrict installation of untrusted applications to reduce attack surface.

🧯 If You Can't Patch

Isolate affected devices from critical networks and sensitive data.
Implement strict application allowlisting to prevent malicious app installation.

🔍 How to Verify

Check if Vulnerable:

Check the operating system version against the affected versions listed above.

Check Version:

iOS/iPadOS/watchOS: Settings > General > About > Version. macOS: Apple menu > About This Mac. tvOS: Settings > General > About.

Verify Fix Applied:

Verify the device is running iOS 13.3.1+, iPadOS 13.3.1+, macOS Catalina 10.15.3+, tvOS 13.3.1+, or watchOS 6.1.2+.

📡 Detection & Monitoring

Log Indicators:

Unexpected kernel panics or crashes
Unusual process spawning with elevated privileges

Network Indicators:

Unusual outbound connections from Apple devices to unknown IPs

SIEM Query:

source="apple-device-logs" AND (event_type="kernel_panic" OR process_privilege="kernel")

📊 Metadata

CVE ID: CVE-2020-3837

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CWE: CWE-787

Published: February 27, 2020

Last Updated: October 23, 2025

🔗 References

https://support.apple.com/HT210918 Release Notes,Vendor Advisory
https://support.apple.com/HT210919 Release Notes,Vendor Advisory
https://support.apple.com/HT210920 Release Notes,Vendor Advisory
https://support.apple.com/HT210921 Release Notes,Vendor Advisory
https://support.apple.com/HT210918 Release Notes,Vendor Advisory
https://support.apple.com/HT210919 Release Notes,Vendor Advisory
https://support.apple.com/HT210920 Release Notes,Vendor Advisory
https://support.apple.com/HT210921 Release Notes,Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3837 US Government Resource

📤 Share & Export

📄 Export Markdown 📋 Export JSON

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