// For flags

CVE-2019-19331

Ubuntu Security Notice USN-7047-1

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

< 1%
*EPSS

Affected Versions

2
*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU utilization. DNS replies with very many resource records might be processed very inefficiently, in extreme cases taking even several CPU seconds for each such uncached message. For example, a few thousand A records can be squashed into one DNS message (limit is 64kB).

knot-resolver versiones anteriores a 4.3.0, es vulnerable a una denegación de servicio por medio de una alta utilización de la CPU. Las respuestas de DNS con muchos registros de recursos podrían ser procesadas de manera muy ineficiente, en casos extremos, tomar incluso varios segundos de CPU para cada mensaje no almacenado en caché. Por ejemplo, algunos miles de registros A pueden ser agrupados en un mensaje DNS (el límite es 64kB).

Vladimír Čunát discovered that Knot Resolver incorrectly handled input during DNSSEC validation. A remote attacker could possibly use this issue to bypass certain validations. Vladimír Čunát discovered that Knot Resolver incorrectly handled input during DNSSEC validation. A remote attacker could possibly use this issue to downgrade DNSSEC-secure domains to a DNSSEC-insecure state, resulting in a domain hijacking attack.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-11-27 CVE Reserved
  • 2019-12-16 CVE Published
  • 2024-08-05 CVE Updated
  • 2024-08-05 First Exploit
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-404: Improper Resource Shutdown or Release
  • CWE-407: Inefficient Algorithmic Complexity
CAPEC
Affected Vendors, Products, and Versions (2)