CVE-2021-34431

mediumpriority · track · 26EPSS 0.011 · 66 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.11% (66th) EPSS

CVSS 4 · medium

Is it mine?

10 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

In Eclipse Mosquitto version 1.6 to 2.0.10, if an authenticated client that had connected with MQTT v5 sent a crafted CONNECT message to the broker a memory leak would occur, which could be used to provide a DoS attack against the broker.

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04mediumAV:N/AC:L/Au:S/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8 · impact 2.9

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 3.6

v3.16.5mediumAV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-401USprimaryCWE-401US

affected products (10)

Products and version ranges known to be affected.

IBM Integration Bus 10.0.0.26all versionscert_bundDEcpe:/a:ibm:integration_bus:10.0.0.26
IBM Integration Bus 10.1all versionscert_bundDEcpe:/a:ibm:integration_bus:10.1
The Eclipse Foundation Eclipse Mosquitto≤ unspecified ≤2.0.10enisa_euvdEU
The Eclipse Foundation Eclipse Mosquitto1.6 → unspecifiedenisa_euvdEU
Eclipse Foundation Eclipse Mosquitto1.6 → 2.0.10fstec_bduRU
АО «НТЦ ИТ РОСА» РОСА ХРОМ≤ 12.4fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 11fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 9fstec_bduRU
eclipse mosquitto1.6 → 2.0.10nvdUScpe:2.3:a:eclipse:mosquitto:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-1094IBM Integration Bus: Mehrere Schwachstellen ermöglichen Denial of ServiceDeutsch2023-04-27csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in IBM Integration Bus ausnutzen, um einen Denial of Service Angriff durchzuführen.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund nvd NVD CVE.org MITRE

published 2021-07-22modified 2026-06-17

related (3,014)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2023-26083US	low3.3OT critical	1.22% (68th)	KEV	2023-04-06
Memory leak vulnerability in Mali GPU Kernel Driver in Midgard GPU Kernel Driver all versions from r6p0 - r32p0, Bifrost GPU Kernel Driver all versions from r0p0 - r42p0, Valhall G…
CVE-2021-1906US	medium5.5OT critical	0.52% (44th)	KEV	2021-05-07
Improper handling of address deregistration on failure can lead to new GPU address allocation failure. in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon C…
CVE-2018-0158US	high8.6OT critical	7.19% (94th)	KEV	2018-03-28
A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a mem…
CVE-2023-25136US	medium6.5	89.8% (100th)	Exploit	2023-02-03
OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be leveraged, by an unaut…
CVE-2016-4232US	high7.5	36.5% (98th)	Exploit	2016-07-13
Adobe Flash Player before 18.0.0.366 and 19.x through 22.x before 22.0.0.209 on Windows and OS X and before 11.2.202.632 on Linux allows attackers to obtain sensitive information f…

+3009 more

references (6)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan