// For flags

CVE-2021-34431

Ubuntu Security Notice USN-6492-1

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

En Eclipse Mosquitto versiones 1.6 hasta 2.0.10, si un cliente autenticado que se había conectado con MQTT versión v5 enviaba un mensaje CONNECT diseñado al broker, ocurriría una pérdida de memoria, que podría ser usada para proporcionar un ataque DoS contra el broker

Kathrin Kleinhammer discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 20.04 LTS. Zhanxiang Song discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input, a remote attacker could possibly use this issue to cause an authorisation bypass. This issue only affected Ubuntu 22.04 LTS and Ubuntu 23.04.

*Credits: Thanks to Kathrin Kleinhammer of OTARIS Interactive Services GmbH for discovering and reporting this issue.
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-06-09 CVE Reserved
  • 2021-07-22 CVE Published
  • 2024-08-04 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-401: Missing Release of Memory after Effective Lifetime
CAPEC
References (1)
URL Tag Source
URL Date SRC
URL Date SRC
URL Date SRC
https://bugs.eclipse.org/bugs/show_bug.cgi?id=573191 2021-08-03
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Eclipse
Search vendor "Eclipse"
 Mosquitto
Search vendor "Eclipse" for product "Mosquitto"
 >= 1.6 <= 2.0.10
Search vendor "Eclipse" for product "Mosquitto" and version " >= 1.6 <= 2.0.10"
-
Affected