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No exploitation reportedFix available

CVE-2021-43400

No exploitation reported by the sources we read.

  • Published2021-11-04
  • WeaknessCWE-416

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2021-11-0423:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-43400?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-43400?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Bluez
BranchAffectedFixed in
5.61= 5.61no fix published
Debian debian linux
BranchAffectedFixed in
10.0= 10.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.19.1read 2026-10-23
  • NVDCVSS 2.06.4read 2026-10-23
  • NVDweakness (CWE)CWE-416read 2026-10-23
  • FIRST EPSSEPSS score1.7 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
2021-11-04
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2021-43400?

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.

Is CVE-2021-43400 actively exploited?

Active exploitation of CVE-2021-43400 has not been confirmed. Its EPSS score was 1.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-43400?

CVE-2021-43400 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

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