CVE-2020-25684

LOW EPSS 89.3%
Published Jan 20, 20215y ago · Modified Jun 17, 20262w ago
3.7 CVSS 3.1
Low
Find Similar
Published Jan 20, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
3.7
Exploitability
2.2
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
89.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-358

Affected Products 10

VendorProductVersionRange
thekelleysdnsmasq* <2.83
fedoraprojectfedora32any
fedoraprojectfedora33any
debiandebian_linux9.0any
debiandebian_linux10.0any
aristaeos*≥4.21  –  <4.21.14m
aristaeos*≥4.22  –  <4.22.9m
aristaeos*≥4.23  –  <4.23.7m
aristaeos*≥4.24  –  <4.24.5m
aristaeos*≥4.25  –  <4.25.2f

References 9

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1889686
    Issue TrackingPatchThird Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html
    Mailing ListThird Party Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
  • security.gentoo.org https://security.gentoo.org/glsa/202101-17
    Third Party Advisory
  • arista.com https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61
    Third Party Advisory
  • debian.org https://www.debian.org/security/2021/dsa-4844
    Third Party Advisory
  • jsof-tech.com https://www.jsof-tech.com/disclosures/dnspooq/
    Third Party Advisory
  • kb.cert.org https://www.kb.cert.org/vuls/id/434904

Remediation

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1889686
    Issue TrackingPatchThird Party Advisory