CVE-2020-25685
Vulnerability from cvelistv5
Published
2021-01-20 00:00
Modified
2024-08-04 15:40
Severity ?
Summary
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.
References
secalert@redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=1889688Issue Tracking, Patch, Third Party Advisory
secalert@redhat.comhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
secalert@redhat.comhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
secalert@redhat.comhttps://security.gentoo.org/glsa/202101-17Third Party Advisory
secalert@redhat.comhttps://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61Third Party Advisory
secalert@redhat.comhttps://www.debian.org/security/2021/dsa-4844Third Party Advisory
secalert@redhat.comhttps://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
Impacted products
n/adnsmasq
Show details on NVD website

To clipboard 

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