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FreeBSD: VID-5B5CF6E5-5B51-11EB-95AC-7F9491278677 (CVE-2020-25684): dnsmasq -- DNS cache poisoning, and DNSSEC buffer overflow, vulnerabilities

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FreeBSD: VID-5B5CF6E5-5B51-11EB-95AC-7F9491278677 (CVE-2020-25684): dnsmasq -- DNS cache poisoning, and DNSSEC buffer overflow, vulnerabilities

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:P/A:N)
Published
09/16/2020
Created
01/22/2021
Added
01/21/2021
Modified
03/08/2021

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)

  • freebsd-upgrade-package-dnsmasq
  • freebsd-upgrade-package-dnsmasq-devel

References

  • CVE-2020-25684
  • USN-4698-1

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