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Fencer Intel
critical 9.1

CVE-2021-43400 json

An issue was discovered in gatt-database.c in BlueZ 5.61.

published 5y ago modified 4mo ago also EUVD-2021-30335

cvss
9.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.7%
EPSS 1.7% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

An issue was discovered in gatt-database.c in BlueZ 5.61. A use-after-free can occur when a client disconnects during D-Bus processing of a WriteValue call.

Patch / fix

  • bluez Debian 14, Debian 13, Debian 12 5.62-1

debian advisories DEBIAN-CVE-2021-43400

  • bluez Ubuntu 18.04 LTS 5.48-0ubuntu3.6
  • bluez Ubuntu 20.04 LTS 5.53-0ubuntu3.4

ubuntu advisories UBUNTU-CVE-2021-43400

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • bluez SLE Workstation Extension 15 SP3, SLE Module for Desktop Applications 15 SP3, SLE Module for Basesystem 15 SP3 +1 more 5.55-150300.3.14.1
  • bluez SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLES 15 SP2-BCL +6 more 5.48-150200.13.17.1
  • bluez SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 5.48-150000.5.41.1

suse advisories SUSE-SU-2022:3981-1SUSE-SU-2022:3691-1SUSE-SU-2022:3687-1

Is CVE-2021-43400 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2021-43400 updated cvss 9.1

bluez: use-after-free in gatt-database.c

  • 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
    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

Exploit prediction

1.66% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:P/A:N

Classification

Weakness

References

Sources

Fencer Intel 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.