CVE-2020-9826 – This vulnerability allows a remote attacker to ... (How to Fix)

Q: What is the severity of CVE-2020-9826?

CVE-2020-9826 has a CVSS score of 7.5 (HIGH). This vulnerability allows a remote attacker to cause a denial of service (DoS) condition on affected Apple devices by sending specially crafted input. It affects iOS, iPadOS, and macOS systems before specific security updates. The issue stems from improper input validation that can be exploited to crash services or systems.

📋 TL;DR

This vulnerability allows a remote attacker to cause a denial of service (DoS) condition on affected Apple devices by sending specially crafted input. It affects iOS, iPadOS, and macOS systems before specific security updates. The issue stems from improper input validation that can be exploited to crash services or systems.

💻 Affected Systems

Products:

iOS
iPadOS
macOS

Versions: Versions before iOS 13.5, iPadOS 13.5, macOS Catalina 10.15.5

Operating Systems: iOS, iPadOS, macOS

Default Config Vulnerable: ⚠️ Yes

Notes: All default configurations of affected versions are vulnerable; no special configuration required for exploitation.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete system crash or service disruption rendering devices unusable until reboot, potentially affecting critical operations.

🟠

Likely Case

Temporary service interruption or application crashes requiring restart, causing productivity loss.

🟢

If Mitigated

Minimal impact with proper network segmentation and updated systems; isolated incidents quickly contained.

🌐 Internet-Facing: MEDIUM - Remote exploitation possible but requires specific conditions; public exposure increases risk.

🏢 Internal Only: LOW - Internal network exploitation less likely unless attacker has internal access; still requires patching.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Apple's description suggests remote exploitation without authentication, but specific exploit details are not publicly disclosed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: iOS 13.5, iPadOS 13.5, macOS Catalina 10.15.5

Vendor Advisory: https://support.apple.com/HT211168

Restart Required: Yes

Instructions:

1. Open Settings app. 2. Go to General > Software Update. 3. Download and install the available update. 4. Restart device when prompted.

🔧 Temporary Workarounds

Network Segmentation

all

Restrict network access to affected devices to reduce attack surface.

Disable Unnecessary Services

all

Turn off non-essential network services on vulnerable devices.

🧯 If You Can't Patch

Implement strict network access controls to limit exposure to untrusted networks.
Monitor systems for unusual crash patterns or denial of service indicators.

🔍 How to Verify

Check if Vulnerable:

Check device version in Settings > General > About > Version. If version is earlier than iOS 13.5, iPadOS 13.5, or macOS 10.15.5, device is vulnerable.

Check Version:

On macOS: sw_vers -productVersion. On iOS/iPadOS: Check Settings > General > About > Version.

Verify Fix Applied:

After update, verify version shows iOS 13.5+, iPadOS 13.5+, or macOS 10.15.5+ in Settings > General > About > Version.

📡 Detection & Monitoring

Log Indicators:

Unexpected application crashes
System reboot logs without user action
Kernel panic logs

Network Indicators:

Unusual inbound traffic patterns to device services
Spike in connection attempts

SIEM Query:

source="apple-device-logs" AND (event="crash" OR event="panic") AND version<"13.5"

📊 Metadata

CVE ID: CVE-2020-9826

CVSS v3 Score: 7.5 (HIGH)

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

CWE: CWE-20

Published: June 9, 2020

Last Updated: November 21, 2024

🔗 References

https://support.apple.com/HT211168 Vendor Advisory
https://support.apple.com/HT211170 Vendor Advisory
https://support.apple.com/HT211168 Vendor Advisory
https://support.apple.com/HT211170 Vendor Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2020-9826, you might also want to check these: