CVE-2021-1812 – This vulnerability allows a malicious applicati... (How to Fix)

Q: What is the severity of CVE-2021-1812?

CVE-2021-1812 has a CVSS score of 7.8 (HIGH). This vulnerability allows a malicious application to execute arbitrary code with system privileges on iOS and iPadOS devices. It affects users running iOS/iPadOS versions before 14.5. The issue was a logic flaw that could be exploited to gain elevated system access.

📋 TL;DR

This vulnerability allows a malicious application to execute arbitrary code with system privileges on iOS and iPadOS devices. It affects users running iOS/iPadOS versions before 14.5. The issue was a logic flaw that could be exploited to gain elevated system access.

💻 Affected Systems

Products:

iPhone
iPad

Versions: iOS/iPadOS versions before 14.5

Operating Systems: iOS, iPadOS

Default Config Vulnerable: ⚠️ Yes

Notes: All devices running vulnerable iOS/iPadOS versions are affected regardless of configuration.

📦 What is this software?

Ipados by Apple

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Iphone Os by Apple

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⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete device compromise with system-level access, allowing installation of persistent malware, data theft, and device control.

🟠

Likely Case

Malicious app could bypass sandbox restrictions to access sensitive data, modify system files, or install additional payloads.

🟢

If Mitigated

Limited impact if only trusted apps from App Store are installed and device is kept updated.

🌐 Internet-Facing: LOW - Requires local app execution, not directly exploitable over network.

🏢 Internal Only: MEDIUM - Risk from malicious apps installed on device, but requires user interaction or app installation.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires malicious app installation and execution on target device. Apple has not disclosed technical details.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: iOS 14.5, iPadOS 14.5

Vendor Advisory: https://support.apple.com/en-us/HT212317

Restart Required: Yes

Instructions:

1. Go to Settings > General > Software Update. 2. Download and install iOS 14.5 or later. 3. Restart device after installation completes.

🔧 Temporary Workarounds

Restrict App Installation

ios

Only allow installation of apps from App Store and trusted developers

Settings > General > Device Management (for enterprise devices)
Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases

🧯 If You Can't Patch

Restrict device to only install apps from App Store
Implement mobile device management (MDM) to control app installation

🔍 How to Verify

Check if Vulnerable:

Check iOS version in Settings > General > About > Version. If version is below 14.5, device is vulnerable.

Check Version:

Settings > General > About > Version

Verify Fix Applied:

Verify iOS version is 14.5 or higher in Settings > General > About > Version.

📡 Detection & Monitoring

Log Indicators:

Unusual app behavior, unexpected system file modifications, privilege escalation attempts

Network Indicators:

Unusual outbound connections from system processes

SIEM Query:

Not applicable - primarily local device exploitation

📊 Metadata

CVE ID: CVE-2021-1812

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

Published: September 8, 2021

Last Updated: November 21, 2024

🔗 References

https://support.apple.com/en-us/HT212317 Release Notes,Vendor Advisory
https://support.apple.com/en-us/HT212317 Release Notes,Vendor Advisory

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