CVE-2021-25407
📋 TL;DR
This vulnerability allows an attacker to write arbitrary data to memory in Samsung's NPU (Neural Processing Unit) driver, potentially leading to system compromise. It affects Samsung devices with NPU hardware prior to the June 2021 security update. Attackers could exploit this to gain elevated privileges or execute arbitrary code.
💻 Affected Systems
- Samsung devices with NPU hardware
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with kernel-level code execution, allowing complete device control, data theft, and persistence.
Likely Case
Local privilege escalation from a compromised app to kernel-level access, enabling further attacks on the device.
If Mitigated
Limited impact with proper app sandboxing and security updates, potentially preventing exploitation entirely.
🎯 Exploit Status
Exploitation requires local access; public proof-of-concept exists demonstrating the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: SMR JUN-2021 Release 1 or later
Vendor Advisory: https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=6
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Install the June 2021 security update or later. 3. Reboot the device after installation.
🔧 Temporary Workarounds
Disable NPU functionality
androidTemporarily disable NPU features if not required, though this may impact device performance.
🧯 If You Can't Patch
- Restrict app installations to trusted sources only
- Implement strict app permission controls and monitor for suspicious behavior
🔍 How to Verify
Check if Vulnerable:
Check device security patch level in Settings > About phone > Software information. If patch level is earlier than June 2021, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Confirm security patch level shows 'June 1, 2021' or later in device settings.📡 Detection & Monitoring
Log Indicators:
- Kernel crash logs related to NPU driver
- Unexpected NPU driver activity
SIEM Query:
Device logs showing security patch level older than June 2021 combined with suspicious process activity🔗 References
- http://packetstormsecurity.com/files/163198/Samsung-NPU-npu_session_format-Out-Of-Bounds-Write.html
- https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=6
- http://packetstormsecurity.com/files/163198/Samsung-NPU-npu_session_format-Out-Of-Bounds-Write.html
- https://security.samsungmobile.com/securityUpdate.smsb?year=2021&month=6
