CVE-2021-31615

Name: CVE-2021-31615
Creator: NVD / NIST
Published: 2021-06-25T12:15:08.43+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.40%

Last modified Jun 17, 2026

CVE-2021-31615 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Unencrypted Bluetooth Low Energy baseband links in Bluetooth Core Specifications 4.0 through 5.2 may permit an adjacent device to inject a crafted packet during the receive window of the listening device before the transmitting device initiates its packet transmission to achieve full MITM status without terminating the link. When applied against devices establishing or using encrypted links, crafted packets may be used to terminate an existing link, but will not compromise the confidentiality or integrity of the link.. EPSS estimates a 0.40% chance of exploitation in the next 30 days.

Description

Unencrypted Bluetooth Low Energy baseband links in Bluetooth Core Specifications 4.0 through 5.2 may permit an adjacent device to inject a crafted packet during the receive window of the listening device before the transmitting device initiates its packet transmission to achieve full MITM status without terminating the link. When applied against devices establishing or using encrypted links, crafted packets may be used to terminate an existing link, but will not compromise the confidentiality or integrity of the link.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

0.40%

31.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Bluetooth	Bluetooth Core Specification	>= 4.0, <= 5.2

References

https://bluetooth.comVendor Advisory
https://www.bluetooth.com/learn-about-bluetooth/key-attributes/bluetooth-security/injectable/Vendor Advisory
https://bluetooth.comVendor Advisory
https://www.bluetooth.com/learn-about-bluetooth/key-attributes/bluetooth-security/injectable/Vendor Advisory

Timeline

Published: Jun 25, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31615?

How severe is CVE-2021-31615?

CVE-2021-31615 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31615?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31615?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST