Skip to main content
The Website Services team at NHS England are testing early designs to understand how you find information. Your views will help us check our ideas work. Sign up to take part in our user research.

KNOB Bluetooth Vulnerability

Security researchers have disclosed details of a vulnerability, known as Key Negotiation of Buletooth (KNOB), in the Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR, formally Bluetooth>encryption keys.

Threat ID:
CC-3182
Category:
Threat Severity:
Low
Threat Vector:
Published:
15 August 2019 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

Security researchers have disclosed details of a vulnerability, known as Key Negotiation of Buletooth (KNOB), in the Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR, formally Bluetooth>encryption keys.

Affected platforms

The following platforms are known to be affected:

Bluetooth

  • Bluetooth BR/EDR specification - Versions 5.1 and earlier

Threat details

They claim that an unauthenticated attacker within Bluetooth range could force other users to agree to use weakened encryption keys. In a standard Bluetooth BR/EDR encrypted connection, the two connecting devices must link and agree on the amount of entropy (between 1 and 16 bytes) to be used to generate the encryption key. If in agreement, the key is generated and the connection is established. With KNOB, it is possible for a third party to intercept their communications in order to reduce the agreed entropy. Encryption keys produced using lower entropy are more susceptible to brute-force attacks, which the third-party can take advantage of to retrieve the keys and perform man-in-the-middle attacks.

For further information:

Remediation steps

Type Step

The following Bluetooth BR/EDR implementers are confirmed to be affected, organisation are encouraged to apply the relevant patches immediately:

CVE Vulnerabilities

Status

CVE-2019-9506

Last edited: 14 February 2020 2:58 pm