CVE-2019-8527 – This is a critical kernel-level buffer overflow... (How to Fix)

Q: What is the severity of CVE-2019-8527?

CVE-2019-8527 has a CVSS score of 9.1 (CRITICAL). This is a critical kernel-level buffer overflow vulnerability in Apple operating systems that allows remote attackers to cause system crashes or corrupt kernel memory. It affects iOS, macOS, tvOS, and watchOS devices. Successful exploitation could lead to denial of service or potential arbitrary code execution with kernel privileges.

📋 TL;DR

This is a critical kernel-level buffer overflow vulnerability in Apple operating systems that allows remote attackers to cause system crashes or corrupt kernel memory. It affects iOS, macOS, tvOS, and watchOS devices. Successful exploitation could lead to denial of service or potential arbitrary code execution with kernel privileges.

💻 Affected Systems

Products:

iOS
macOS
tvOS
watchOS

Versions: Versions prior to iOS 12.2, macOS Mojave 10.14.4, tvOS 12.2, watchOS 5.2

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

Default Config Vulnerable: ⚠️ Yes

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

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote attacker gains kernel-level code execution, leading to complete system compromise, data theft, or persistent backdoor installation.

🟠

Likely Case

Remote attacker causes system crashes (kernel panics) resulting in denial of service and potential data loss from unsaved work.

🟢

If Mitigated

With proper patching, no impact as the vulnerability is fully addressed in updated versions.

🌐 Internet-Facing: HIGH - Remote exploitation possible without authentication, affecting internet-connected Apple devices.

🏢 Internal Only: MEDIUM - Internal network exploitation possible, but requires network access to vulnerable devices.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Buffer overflow in kernel memory requires precise exploitation but remote unauthenticated access lowers barrier.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: iOS 12.2, macOS Mojave 10.14.4, tvOS 12.2, watchOS 5.2

Vendor Advisory: https://support.apple.com/HT209599

Restart Required: Yes

Instructions:

1. Open Settings/System Preferences. 2. Navigate to Software Update. 3. Install available updates. 4. Restart device when prompted.

🔧 Temporary Workarounds

Network Segmentation

all

Isolate Apple devices from untrusted networks to reduce attack surface.

Disable Unnecessary Services

all

Turn off network services not required for device functionality.

🧯 If You Can't Patch

Implement strict network access controls to limit exposure to trusted sources only.
Monitor for system crashes/kernel panics and investigate any unusual activity immediately.

🔍 How to Verify

Check if Vulnerable:

Check system version: iOS: Settings > General > About > Version; macOS: Apple menu > About This Mac; tvOS: Settings > General > About; watchOS: Watch app on iPhone > General > About.

Check Version:

macOS: sw_vers -productVersion; iOS/tvOS/watchOS: Check via device settings as above.

Verify Fix Applied:

Confirm version is equal to or newer than: iOS 12.2, macOS 10.14.4, tvOS 12.2, watchOS 5.2.

📡 Detection & Monitoring

Log Indicators:

Kernel panic logs
System crash reports
Unexpected reboots

Network Indicators:

Unusual network traffic to Apple devices
Connection attempts to kernel services

SIEM Query:

source="apple_system_logs" AND (event="kernel_panic" OR event="system_crash")

📊 Metadata

CVE ID: CVE-2019-8527

CVSS v3 Score: 9.1 (CRITICAL)

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

CWE: CWE-120

Published: December 18, 2019

Last Updated: November 21, 2024

🔗 References

https://support.apple.com/HT209599 Vendor Advisory
https://support.apple.com/HT209600 Vendor Advisory
https://support.apple.com/HT209601 Vendor Advisory
https://support.apple.com/HT209602 Vendor Advisory
https://support.apple.com/HT209599 Vendor Advisory
https://support.apple.com/HT209600 Vendor Advisory
https://support.apple.com/HT209601 Vendor Advisory
https://support.apple.com/HT209602 Vendor Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2019-8527, you might also want to check these: