CVE-2021-25424
📋 TL;DR
This vulnerability allows attackers to bypass Bluetooth authentication on Tizen devices, enabling unauthorized access and control without user interaction. It affects Tizen-based Samsung devices with vulnerable Bluetooth frameworks prior to the June 2021 firmware update.
💻 Affected Systems
- Samsung Tizen-based devices (smart TVs, wearables, IoT devices)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete takeover of Bluetooth-connected devices, enabling data theft, unauthorized device control, and potential lateral movement to other connected systems.
Likely Case
Unauthorized access to Bluetooth devices for data interception, device manipulation, or privacy violations without user awareness.
If Mitigated
Limited impact with proper Bluetooth security controls, device isolation, and updated firmware preventing authentication bypass.
🎯 Exploit Status
Exploitation requires Bluetooth proximity but no authentication, making it relatively simple for attackers within range
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware update JUN-2021 Release
Vendor Advisory: https://security.samsungmobile.com/serviceWeb.smsb?year=2021&month=6
Restart Required: Yes
Instructions:
1. Check device firmware version. 2. Navigate to Settings > Support > Software Update. 3. Install available updates. 4. Restart device after update completes.
🔧 Temporary Workarounds
Disable Bluetooth
allTurn off Bluetooth functionality to prevent exploitation
Restrict Bluetooth Visibility
allSet Bluetooth to non-discoverable mode to reduce attack surface
🧯 If You Can't Patch
- Disable Bluetooth when not in use or in untrusted environments
- Implement network segmentation to isolate Bluetooth devices from critical systems
🔍 How to Verify
Check if Vulnerable:
Check Tizen firmware version: Settings > Support > About This TV > Software Version. If version predates JUN-2021 Release, device is vulnerable.Check Version:
Not applicable via command line on consumer Tizen devices; use GUI settings menuVerify Fix Applied:
Verify firmware version shows JUN-2021 Release or later after update installation📡 Detection & Monitoring
Log Indicators:
- Unexpected Bluetooth pairing events
- Unauthorized device connections in Bluetooth logs
- Multiple failed authentication attempts followed by successful connection
Network Indicators:
- Unusual Bluetooth traffic patterns
- Connections from unknown MAC addresses
- Bluetooth pairing requests without user interaction
SIEM Query:
Not typically applicable for consumer Bluetooth devices; enterprise monitoring would focus on Bluetooth gateway logs if available