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.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published: 2021-01-20T15:22:21

Updated: 2024-08-04T15:40:36.670Z

Reserved: 2020-09-16T00:00:00

Link: CVE-2020-25684

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-01-20T16:15:14.163

Modified: 2024-11-21T05:18:27.603

Link: CVE-2020-25684

cve-icon Redhat

Severity : Moderate

Publid Date: 2021-01-19T00:00:00Z

Links: CVE-2020-25684 - Bugzilla