CVE-2021-25487

7.3 HIGH

📋 TL;DR

This vulnerability in Samsung modem interface drivers allows out-of-bounds memory read and arbitrary code execution through invalid function pointer dereference. It affects Samsung mobile devices with vulnerable modem drivers prior to October 2021 security updates. Attackers could gain kernel-level privileges on affected devices.

💻 Affected Systems

Products:
  • Samsung mobile devices with Exynos modems
Versions: All versions prior to SMR Oct-2021 Release 1
Operating Systems: Android with Samsung modem drivers
Default Config Vulnerable: ⚠️ Yes
Notes: Specifically affects Samsung's modem interface driver implementation on Exynos-based devices.

📦 What is this software?

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

Android by Samsung

Android is Google's open-source mobile operating system powering over 3 billion devices worldwide, including smartphones, tablets, smart TVs, automotive systems, wearables, and IoT devices. As the world's dominant mobile OS with approximately 72% global market share, Android serves as the foundation...

Learn more about Android →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete device compromise with kernel-level code execution, allowing persistent malware installation, data theft, and device control.

🟠

Likely Case

Privilege escalation to kernel mode, enabling surveillance, data exfiltration, and installation of persistent backdoors.

🟢

If Mitigated

Limited impact with proper patch management and device isolation, though kernel vulnerabilities remain serious.

🌐 Internet-Facing: MEDIUM
🏢 Internal Only: HIGH

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: LIKELY
Unauthenticated Exploit: ✅ No
Complexity: MEDIUM

Requires local access or malware delivery, but kernel vulnerabilities are highly valuable to attackers.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: SMR Oct-2021 Release 1 and later

Vendor Advisory: https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=10

Restart Required: Yes

Instructions:

1. Check for Samsung security updates in device settings. 2. Install October 2021 or later security patch. 3. Reboot device after installation.

🔧 Temporary Workarounds

Disable unnecessary modem interfaces

android

Reduce attack surface by disabling unused modem features

🧯 If You Can't Patch

  • Isolate affected devices from critical networks
  • Implement strict application whitelisting and monitoring

🔍 How to Verify

Check if Vulnerable:

Check Android security patch level in Settings > About phone > Software information. If before October 2021, device is vulnerable.

Check Version:

adb shell getprop ro.build.version.security_patch

Verify Fix Applied:

Verify security patch level shows October 2021 or later in device settings.

📡 Detection & Monitoring

Log Indicators:

  • Kernel panic logs
  • Modem driver crash reports
  • Unexpected privilege escalation attempts

Network Indicators:

  • Unusual modem/baseband communication patterns
  • Suspicious kernel module loading

SIEM Query:

Device logs showing modem driver crashes or kernel access violations

🔗 References

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