CVE-2020-26557: High severity Bluetooth Mesh profile vulnerability
Mesh Provisioning in the Bluetooth Mesh profile 1.0 and 1.0.1 may permit a nearby device (without possession of the AuthValue used in the provisioning protocol) to determine the AuthValue via a brute-force attack (unless the AuthValue is sufficiently random and changed each time).
Other sources
The Bluetooth Mesh Profile Specification versions 1.0 and 1.0.1 Mesh Provisioning procedure could allow an attacker observing or taking part in the provisioning to brute force the AuthValue if has a fixed value or is selected predictably or with low entropy. If successful, an attacker may be able to identify the AuthValue and authenticate to both the Provisioner and provisioned devices, permitting a MITM attack on a future provisioning attempt with the same AuthValue.
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Use a sufficiently random, high-entropy AuthValue and change it for every provisioning attempt; do not use a fixed, predictable, or low-entropy value.
Bluetooth Mesh Provisioning AuthValue = sufficiently random and changed each time
Event History
Frequently Asked Questions
What is CVE-2020-26557?
CVE-2020-26557 is a vulnerability in the Bluetooth Mesh profile 1.0 and 1.0.1 that could allow a nearby device to determine the AuthValue via a brute-force attack.
How does CVE-2020-26557 affect Bluetooth Mesh profile?
CVE-2020-26557 affects the Bluetooth Mesh profile versions 1.0 and 1.0.1.
What is the severity of CVE-2020-26557?
The severity of CVE-2020-26557 is high, with a severity value of 7.5.
How can a nearby device exploit CVE-2020-26557?
A nearby device can exploit CVE-2020-26557 by conducting a brute-force attack to determine the AuthValue used in the provisioning protocol.
Are there any fixes available for CVE-2020-26557?
To mitigate CVE-2020-26557, it is recommended to ensure that the AuthValue is sufficiently random and changed each time.