CVE-2020-25684

3.7 LOW
Published: January 20, 2021 Modified: November 04, 2025

Description

A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:reply_query() if the reply destination address/port is used by the pending forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1889686
Source: secalert@redhat.com
Issue Tracking Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html
Source: secalert@redhat.com
Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202101-17
Source: secalert@redhat.com
Third Party Advisory
https://www.debian.org/security/2021/dsa-4844
Source: secalert@redhat.com
Third Party Advisory
https://www.jsof-tech.com/disclosures/dnspooq/
Source: secalert@redhat.com
Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1889686
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202101-17
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://www.debian.org/security/2021/dsa-4844
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://www.jsof-tech.com/disclosures/dnspooq/
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://www.kb.cert.org/vuls/id/434904
Source: af854a3a-2127-422b-91ae-364da2661108

17 reference(s) from NVD

Quick Stats

CVSS v3 Score
3.7 / 10.0
EPSS (Exploit Probability)
0.3%
50th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

arista debian fedoraproject thekelleys