HOMEVULNERABILITIESCVE-2021-43400
CRITICAL

CVE-2021-43400

CWE-416Published: November 4, 2021· Updated: Jun 17, 2026

9.1
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-43400 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 9.1.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected Vendors & Products

bluez1 product(s)
bluez
Debian1 product(s)
debian linux
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (5)

Quick Facts

CVE IDCVE-2021-43400
CVSS Score9.1 / 10
SeverityCRITICAL
WeaknessCWE-416
CISA KEVNo
Affected2 vendor(s)
PublishedNov 4, 2021

Related CVEs (CWE-416)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-43400 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.