CVE-2020-25685

A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25684 the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.
Configurations

Configuration 1 (hide)

cpe:2.3:a:thekelleys:dnsmasq:*:*:*:*:*:*:*:*

Configuration 2 (hide)

OR cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*

Configuration 3 (hide)

cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

Configuration 4 (hide)

OR cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*

History

07 Nov 2023, 03:20

Type Values Removed Values Added
References
  • {'url': 'https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/', 'name': 'FEDORA-2021-2e4c3d5a9d', 'tags': ['Mailing List', 'Third Party Advisory'], 'refsource': 'FEDORA'}
  • {'url': 'https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/', 'name': 'FEDORA-2021-84440e87ba', 'tags': ['Mailing List', 'Third Party Advisory'], 'refsource': 'FEDORA'}
  • () https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/ -
  • () https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/ -

Information

Published : 2021-01-20 16:15

Updated : 2024-02-28 18:08


NVD link : CVE-2020-25685

Mitre link : CVE-2020-25685

CVE.ORG link : CVE-2020-25685


JSON object : View

Products Affected

fedoraproject

  • fedora

arista

  • eos

thekelleys

  • dnsmasq

debian

  • debian_linux
CWE
CWE-326

Inadequate Encryption Strength