CVE-2021-34147

Description

The Bluetooth Classic implementation in the Cypress WICED BT stack through 2.9.0 for CYW20735B1 does not properly handle the reception of a malformed LMP timing accuracy response followed by multiple reconnections to the link slave, allowing attackers to exhaust device BT resources and eventually trigger a crash via multiple attempts of sending a crafted LMP timing accuracy response followed by a sudden reconnection with a random BDAddress.

Related CPE's

ocypresswireless_internet_connectivity_for_embedded_devices********

vulnerable

hcypresscyw20735b1-*******

References

https://www.cypress.com/documentation/datasheets/cyw20735b1-single-chip-bluetooth-transceiver-wireless-input-devices

Vendor Advisory

https://dl.packetstormsecurity.net/papers/general/braktooth.pdf

Technical DescriptionThird Party Advisory

CvssV3 impact

BaseSeverity

MEDIUM

ConfidentialityImpact

NONE

AttackComplexity

LOW

Scope

UNCHANGED

AttackVector

ADJACENT_NETWORK

AvailabilityImpact

HIGH

IntegrityImpact

NONE

PrivilegesRequired

NONE

BaseScore

6.5

VectorString

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Version

3.1

UserInteraction

NONE

CvssV2 impact

AccessComplexity

LOW

ConfidentialityImpact

NONE

AvailabilityImpact

COMPLETE

IntegrityImpact

NONE

BaseScore

6.1

VectorString

AV:A/AC:L/Au:N/C:N/I:N/A:C

Version

2.0

AccessVector

ADJACENT_NETWORK

Authentication

NONE

Created by Yello
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