CVE-2019-19331

HIGH
7.5
CVSS Score
Published: December 16, 2019 at 12:00 AM UTC
Updated: June 17, 2026 at 02:26 AM UTC
3 products affected across 3 vendorsDebian LinuxKnot ResolverKnot Resolver

Using knot-resolver by CZ.NIC?

Get instant alerts when new vulnerabilities affect knot-resolver - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.5
Exploit prediction
EPSS 2%

Description

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).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.3.0
Affected range stops below 4.3.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-407CWE-404

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card