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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: Nov 13, 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

Mate 10

Earlier than ALP-AL00B 9.1.0.333(C00E333R2P1T8) versions

ALP-AL00B 9.1.0.333(C00E333R2P1T8)

Mate 10 Porsche design

Earlier than BLA-AL00B 9.1.0.329(C786E320R2P1T8) versions

BLA-AL00B 9.1.0.329(C786E320R2P1T8)

Mate 20 X

Earlier than Ever-AL00B 9.1.0.135(C00E133R2P1) versions

Ever-AL00B 9.1.0.135(C00E133R2P1)

Earlier than Ever-L29B 9.1.0.338(C185E3R3P1) versions

Ever-L29B 9.1.0.338(C185E3R3P1)

Earlier than Ever-L29B 9.1.0.320(C432E3R1P12) versions

Ever-L29B 9.1.0.320(C432E3R1P12)

Mate 20 RS Porsche design

Earlier than Laya-AL00EP 9.1.0.135(C786E133R3P1) versions

Laya-AL00EP 9.1.0.135(C786E133R3P1)

P20

Earlier than Emily-AL00A 9.1.0.333(C00E333R1P1T8) versions

Emily-AL00A 9.1.0.333(C00E333R1P1T8)








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.

1.For Matebook, Magicbook series laptops, follow the Microsoft security advisories to implement patch.

2.The product that supports automatic update will receive a system update prompt. You can install the update to fix the vulnerability.

This vulnerability was reported by CERT/CC.

2019-11-13 V1.1 UPDATED Updated the affected version and fix version information

2019-08-28 V1.0 INITIAL

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