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Red Hat: CVE-2020-25684: CVE-2020-25684 dnsmasq: loose address/port check in reply_query() makes forging replies easier for an off-path attacker (Multiple Advisories)

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Red Hat: CVE-2020-25684: CVE-2020-25684 dnsmasq: loose address/port check in reply_query() makes forging replies easier for an off-path attacker (Multiple Advisories)

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:P/A:N)
Published
01/19/2021
Created
01/20/2021
Added
01/20/2021
Modified
12/15/2023

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.

Solution(s)

  • redhat-upgrade-dnsmasq
  • redhat-upgrade-dnsmasq-debuginfo
  • redhat-upgrade-dnsmasq-debugsource
  • redhat-upgrade-dnsmasq-utils
  • redhat-upgrade-dnsmasq-utils-debuginfo

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