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Description

A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity.

PUBLISHED Reserved 2021-03-16 | Published 2021-04-08 | Updated 2025-12-03 | Assigner redhat

Problem types

CWE-358

References

bugzilla.redhat.com/show_bug.cgi?id=1939368

lists.fedoraproject.org/...GHURNEHHUBSW45KMIZ4FNBCSUPWPGV5V/ (FEDORA-2021-62a5062b2d) vendor-advisory

lists.fedoraproject.org/...FHG7GWSQWKF7JXIMLOGJBKZWBB4VIAJ7/ (FEDORA-2021-9433bedebd) vendor-advisory

lists.fedoraproject.org/...CVTJUOFFFHINLKWAOC2ZSC5MOPD4SJ24/ (FEDORA-2021-5cd2571751) vendor-advisory

security.gentoo.org/glsa/202105-20 (GLSA-202105-20) vendor-advisory

www.oracle.com/security-alerts/cpujan2022.html

bugzilla.redhat.com/show_bug.cgi?id=1939368

lists.fedoraproject.org/...GHURNEHHUBSW45KMIZ4FNBCSUPWPGV5V/ (FEDORA-2021-62a5062b2d) vendor-advisory

lists.fedoraproject.org/...FHG7GWSQWKF7JXIMLOGJBKZWBB4VIAJ7/ (FEDORA-2021-9433bedebd) vendor-advisory

lists.fedoraproject.org/...CVTJUOFFFHINLKWAOC2ZSC5MOPD4SJ24/ (FEDORA-2021-5cd2571751) vendor-advisory

security.gentoo.org/glsa/202105-20 (GLSA-202105-20) vendor-advisory

www.oracle.com/security-alerts/cpujan2022.html

cve.org (CVE-2021-3448)

nvd.nist.gov (CVE-2021-3448)

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