CVE-2020-25684

Publication date 19 January 2021

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

3.7 · Low

Score breakdown

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.

Status

Package Ubuntu Release Status
dnsmasq 24.10 oracular
Fixed 2.82-1ubuntu2
24.04 LTS noble
Fixed 2.82-1ubuntu2
23.10 mantic
Fixed 2.82-1ubuntu2
23.04 lunar
Fixed 2.82-1ubuntu2
22.10 kinetic
Fixed 2.82-1ubuntu2
22.04 LTS jammy
Fixed 2.82-1ubuntu2
21.10 impish
Fixed 2.82-1ubuntu2
21.04 hirsute
Fixed 2.82-1ubuntu2
20.10 groovy
Fixed 2.82-1ubuntu1.1
20.04 LTS focal
Fixed 2.80-1.1ubuntu1.2
18.04 LTS bionic
Fixed 2.79-1ubuntu0.2
16.04 LTS xenial
Fixed 2.75-1ubuntu0.16.04.7
14.04 LTS trusty
Needs evaluation

Severity score breakdown

Parameter Value
Base score 3.7 · Low
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact Low
Availability impact None
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N