CVE-2021-25470
📋 TL;DR
This vulnerability in Samsung's TEEGRIS secure OS allows attackers to bypass caller verification checks in SMC calls, potentially compromising the Trusted Execution Environment. It affects Samsung mobile devices running TEEGRIS secure OS prior to October 2021 security updates. The vulnerability could allow unauthorized access to secure memory and sensitive operations.
💻 Affected Systems
- Samsung mobile devices with TEEGRIS secure OS
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the Trusted Execution Environment, allowing extraction of encryption keys, biometric data, and other sensitive information protected by the TEE.
Likely Case
Privilege escalation allowing unauthorized access to secure functions and data within the TEE, potentially enabling further attacks on the device.
If Mitigated
Limited impact if device is patched and proper security controls are in place, though TEE compromise remains a serious concern.
🎯 Exploit Status
Exploitation requires local access and knowledge of TEE internals. No public exploit code has been disclosed.
🛠️ 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 available security updates in device settings. 2. Install October 2021 security patch or later. 3. Reboot device after installation.
🔧 Temporary Workarounds
Disable unnecessary TEE services
androidReduce attack surface by disabling unused secure services and applications that rely on TEE functionality.
🧯 If You Can't Patch
- Restrict physical access to devices and implement strong device management policies
- Monitor for unusual TEE-related activity and implement application allowlisting
🔍 How to Verify
Check if Vulnerable:
Check device security patch level in Settings > About phone > Software information. If patch level is earlier than October 2021, device is vulnerable.Check Version:
Settings > About phone > Software information > Android security patch levelVerify Fix Applied:
Verify security patch level shows October 2021 or later in device settings.📡 Detection & Monitoring
Log Indicators:
- Unusual TEE service calls
- Failed SMC call attempts
- Unexpected privilege escalation attempts
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Not applicable - requires device-level monitoring