CVE-2020-14312Network attack vector

Third-party DDoS via open DNS resolver

Published Feb 5, 2021 · Updated Aug 4, 2024

Improper access control in dnsmasq on Fedora before 31 and all Red Hat Enterprise Linux versions allows remote attackers to enable DDoS. The distro default omits local-service, so dnsmasq listens on every interface and recursively answers DNS queries from outside its local subnet. Exposure requires dnsmasq to run with that default and incoming DNS to pass the firewall; the resolver then amplifies traffic against third-party victims.

CVSS severity5.9
Medium
EPSS probability1.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in dnsmasq on Fedora before 31 and all Red Hat Enterprise Linux versions allows remote attackers to enable DDoS. The distro default omits local-service, so dnsmasq listens on every interface and recursively answers DNS queries from outside its local subnet. Exposure requires dnsmasq to run with that default and incoming DNS to pass the firewall; the resolver then amplifies traffic against third-party victims.

The record

CVE
CVE-2020-14312
Published
Feb 5, 2021
Updated
Aug 4, 2024
Vendor
Simon Kelley
Product
dnsmasq
Classifications
CWE-284, T1498.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 5, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=all RHEL versions
  2. Affected versionversion=Fedora version prior to 31

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Simon Kelley · dnsmasqversion=all RHEL versions; version=Fedora version prior to 31

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.9NIST NVDCVSS:3.1/AV:N/AC:H/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-284Improper Access Control
T1498.002Reflection Amplification

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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