CVE-2018-1110Network attack vector

Resolver crash via malformed DNS packets

Published Mar 30, 2021 · Updated Aug 5, 2024

Improper input validation in CZ.NIC Knot Resolver 2.2.0 and earlier allows remote attackers to crash the resolver with malformed DNS packets. The resolver processes crafted packet structures without sufficient validation, and correcting the defects required major data-structure changes. An unauthenticated network sender can terminate the resolver process, interrupting DNS resolution without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in CZ.NIC Knot Resolver 2.2.0 and earlier allows remote attackers to crash the resolver with malformed DNS packets. The resolver processes crafted packet structures without sufficient validation, and correcting the defects required major data-structure changes. An unauthenticated network sender can terminate the resolver process, interrupting DNS resolution without reported data disclosure or modification.

The record

CVE
CVE-2018-1110
Published
Mar 30, 2021
Updated
Aug 5, 2024
Vendor
CZ.NIC
Product
Knot Resolver
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Knot Resolver 2.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CZ.NIC · Knot Resolverversion=Knot Resolver 2.3.0

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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