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Fencer Vulns
medium 6.8

CVE-2021-37577 json

Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specificati…

published 2024-10-01 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-24138

cvss
6.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specifications 2.1 through 5.3 may permit an unauthenticated man-in-the-middle attacker to identify the Passkey used during pairing by reflection of a crafted public key with the same X coordinate as the offered public key and by reflection of the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. This is a related issue to CVE-2020-26558.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-37577 updated cvss 6.8

bluez: Bluetooth Passkey Reflection Attack in Secure Pairing

  • Red Hat Enterprise Linux 6 bluez, bluez-alsa, bluez-cups, bluez-libs, bluez-compat, bluez-gstreamer Red Hat Enterprise Linux 7 bluez, bluez-cups, bluez-libs, bluez-hid2hci Red Hat Enterprise Linux 8 bluez, bluez-cups, bluez-libs, bluez-obexd, bluez-hid2hci Red Hat Enterprise Linux 9 bluez, bluez-cups, bluez-libs, bluez-obexd Red Hat Enterprise Linux 10 bluez, bluez-cups, bluez-libs, bluez-obexd
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L
CNA 3.1 6.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.