CVE-2020-9895 – This is a critical use-after-free memory corrup... (How to Fix)

Q: What is the severity of CVE-2020-9895?

CVE-2020-9895 has a CVSS score of 9.8 (CRITICAL). This is a critical use-after-free memory corruption vulnerability in Apple's iOS, iPadOS, tvOS, watchOS, Safari, iTunes, and iCloud for Windows. A remote attacker could exploit this to crash applications or execute arbitrary code on affected devices. All users running vulnerable versions of these Apple products are affected.

📋 TL;DR

This is a critical use-after-free memory corruption vulnerability in Apple's iOS, iPadOS, tvOS, watchOS, Safari, iTunes, and iCloud for Windows. A remote attacker could exploit this to crash applications or execute arbitrary code on affected devices. All users running vulnerable versions of these Apple products are affected.

💻 Affected Systems

Products:

iOS
iPadOS
tvOS
watchOS
Safari
iTunes for Windows
iCloud for Windows

Versions: Versions prior to iOS 13.6, iPadOS 13.6, tvOS 13.4.8, watchOS 6.2.8, Safari 13.1.2, iTunes 12.10.8 for Windows, iCloud for Windows 11.3, iCloud for Windows 7.20

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

Default Config Vulnerable: ⚠️ Yes

Notes: All default configurations of affected products are vulnerable. No special configuration required for exploitation.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution with full system compromise, allowing attacker to install malware, steal data, or create persistent access.

🟠

Likely Case

Application crashes leading to denial of service, with potential for limited code execution in some scenarios.

🟢

If Mitigated

Minimal impact if patched; unpatched systems remain vulnerable to exploitation attempts.

🌐 Internet-Facing: HIGH - Remote attackers can exploit this without user interaction in some configurations.

🏢 Internal Only: MEDIUM - Requires user interaction or internal network access in some scenarios.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Use-after-free vulnerabilities typically require some exploitation sophistication but are commonly weaponized. Remote exploitation is possible via web content in Safari or other affected applications.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: iOS 13.6, iPadOS 13.6, tvOS 13.4.8, watchOS 6.2.8, Safari 13.1.2, iTunes 12.10.8 for Windows, iCloud for Windows 11.3, iCloud for Windows 7.20

Vendor Advisory: https://support.apple.com/HT211288

Restart Required: Yes

Instructions:

1. For iOS/iPadOS: Go to Settings > General > Software Update and install the latest update. 2. For macOS: Update Safari through System Preferences > Software Update. 3. For Windows: Update iTunes and iCloud through the Microsoft Store or Apple Software Update. 4. For tvOS/watchOS: Update through device settings.

🔧 Temporary Workarounds

Disable JavaScript in Safari

all

Temporarily reduces attack surface by disabling JavaScript execution in Safari browser

Safari > Preferences > Security > Uncheck 'Enable JavaScript'

Network Segmentation

all

Isolate vulnerable devices from untrusted networks

🧯 If You Can't Patch

Isolate affected devices from internet and untrusted networks
Implement application whitelisting to prevent unauthorized code execution

🔍 How to Verify

Check if Vulnerable:

Check current version against patched versions: iOS/iPadOS: Settings > General > About > Version; macOS: Safari > About Safari; Windows: Help > About in iTunes/iCloud

Check Version:

iOS: settings read com.apple.SystemVersion; macOS: defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionString

Verify Fix Applied:

Confirm version matches or exceeds patched versions listed in fix_official.patch_version

📡 Detection & Monitoring

Log Indicators:

Application crashes of affected Apple software
Memory access violation logs
Unexpected process termination

Network Indicators:

Unusual outbound connections from Apple devices
Suspicious web requests to Apple services

SIEM Query:

source="apple-device-logs" AND (event_type="crash" OR event_type="memory_violation") AND process_name IN ("Safari", "MobileSafari", "iTunes", "iCloud")

📊 Metadata

CVE ID: CVE-2020-9895

CVSS v3 Score: 9.8 (CRITICAL)

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

CWE: CWE-416

Published: October 16, 2020

Last Updated: November 21, 2024

🔗 References

https://support.apple.com/HT211288 Vendor Advisory
https://support.apple.com/HT211290 Vendor Advisory
https://support.apple.com/HT211291 Vendor Advisory
https://support.apple.com/HT211292 Vendor Advisory
https://support.apple.com/HT211293 Vendor Advisory
https://support.apple.com/HT211294 Vendor Advisory
https://support.apple.com/HT211295 Vendor Advisory
https://support.apple.com/HT211288 Vendor Advisory
https://support.apple.com/HT211290 Vendor Advisory
https://support.apple.com/HT211291 Vendor Advisory
https://support.apple.com/HT211292 Vendor Advisory
https://support.apple.com/HT211293 Vendor Advisory
https://support.apple.com/HT211294 Vendor Advisory
https://support.apple.com/HT211295 Vendor Advisory

📤 Share & Export

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🔗 Related Vulnerabilities

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