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Security Advisory - Key Negotiation of Bluetooth (KNOB) Vulnerability

  • SA No:huawei-sa-20190828-01-knob
  • Initial Release Date: Aug 28, 2019
  • Last Release Date: Aug 28, 2019

The KNOB (Key Negotiation of Bluetooth) vulnerability exists in the encryption key negotiation process between two Bluetooth BR/EDR devices. The negotiation process is not encrypted and no authentication is performed. An unauthenticated, adjacent attacker can initiate a man-in-the-middle attack to reduce the negotiated entropy length used for secure connections to a single octet. Successful exploit could cause the encryption key being vulnerable to brute force. (Vulnerability ID: HWPSIRT-2019-08118)
This vulnerability has been assigned a Common Vulnerabilities and Exposures (CVE) ID: CVE-2019-9506.
Huawei has released software updates to fix this vulnerability. This advisory is available at the following link:
http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20190828-01-knob-en

Product Name

Affected Version

Resolved Product and Version

Matebook, Magicbook series laptops

Running the affected Windows operating system

Follow the Microsoft security advisory to implement patch

Successful exploit could cause the encryption key being vulnerable to brute force.

The vulnerability classification has been performed by using the CVSSv3 scoring system (http://www.first.org/cvss/specification-document).

Base Score: 8.0 (AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N)

Temporal Score: 7.4 (E:F/RL:O/RC:C)

Overall Score: 7.4

This vulnerability can be exploited only when the following conditions are present: 

The attacker gains access to the device network. 

Vulnerability details: 

The KNOB (Key Negotiation of Bluetooth) vulnerability exists in the encryption key negotiation process between two Bluetooth BR/EDR devices. The negotiation process is not encrypted and no authentication is performed. An unauthenticated, adjacent attacker can initiate a man-in-the-middle attack to reduce the negotiated entropy length used for secure connections to a single octet. Successful exploit could cause the encryption key being vulnerable to brute force.

Follow the Microsoft security advisories to implement patch.

This vulnerability was reported by CERT/CC.

2019-08-28 V1.0 INITIAL

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