CVE-2020-26559
📋 TL;DR
This vulnerability allows a nearby Bluetooth device to bypass authentication during Bluetooth Mesh provisioning, potentially gaining unauthorized access to the mesh network. It affects devices using Bluetooth Mesh Profile 1.0 and 1.0.1. Attackers can identify the AuthValue without brute-forcing, compromising network security.
💻 Affected Systems
- Devices implementing Bluetooth Mesh Profile
📦 What is this software?
Mesh Profile by Bluetooth
Mesh Profile by Bluetooth
⚠️ Risk & Real-World Impact
Worst Case
Unauthorized devices join the Bluetooth mesh network, enabling data interception, device impersonation, and potential control over connected IoT devices.
Likely Case
Nearby attackers gain unauthorized access to Bluetooth mesh networks, potentially compromising smart home, industrial, or building automation systems.
If Mitigated
With proper network segmentation and monitoring, impact is limited to isolated mesh segments with minimal data exposure.
🎯 Exploit Status
Requires proximity to target device during provisioning process. No public exploit code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Bluetooth Mesh Profile 1.1 or later
Vendor Advisory: https://www.bluetooth.com/learn-about-bluetooth/key-attributes/bluetooth-security/reporting-security/
Restart Required: Yes
Instructions:
1. Check device manufacturer for Bluetooth Mesh firmware updates. 2. Update to Bluetooth Mesh Profile 1.1 or later. 3. Restart affected devices. 4. Re-provision mesh network with updated security.
🔧 Temporary Workarounds
Disable Bluetooth Mesh Provisioning
allTemporarily disable Bluetooth Mesh provisioning until patches can be applied.
Vendor-specific commands to disable mesh provisioning
Physical Security Controls
allRestrict physical access to devices during provisioning to prevent nearby attackers.
🧯 If You Can't Patch
- Segment Bluetooth mesh networks from critical systems
- Implement network monitoring for unauthorized device provisioning attempts
🔍 How to Verify
Check if Vulnerable:
Check Bluetooth Mesh Profile version in device specifications or firmware documentation. If version is 1.0 or 1.0.1, device is vulnerable.Check Version:
Vendor-specific command to check Bluetooth Mesh Profile versionVerify Fix Applied:
Confirm Bluetooth Mesh Profile version is 1.1 or later after update. Test provisioning with security monitoring enabled.📡 Detection & Monitoring
Log Indicators:
- Unexpected device provisioning events
- Multiple failed provisioning attempts from unknown devices
Network Indicators:
- Unauthorized devices appearing in Bluetooth mesh network
- Unusual provisioning traffic patterns
SIEM Query:
Search for Bluetooth provisioning events from unauthorized MAC addresses or outside expected time windows🔗 References
- https://kb.cert.org/vuls/id/799380
- https://www.bluetooth.com/learn-about-bluetooth/key-attributes/bluetooth-security/reporting-security/
- https://kb.cert.org/vuls/id/799380
- https://www.bluetooth.com/learn-about-bluetooth/key-attributes/bluetooth-security/reporting-security/
- https://www.kb.cert.org/vuls/id/799380
