UBUNTU-CVE-2020-25684

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Source
https://ubuntu.com/security/CVE-2020-25684
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-25684.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2020-25684
Upstream
Downstream
Related
Published
2021-01-19T00:00:00Z
Modified
2025-09-08T16:46:20Z
Severity
  • 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:Pro:14.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq@2.68-1ubuntu0.2+esm3?arch=source&distro=esm-infra-legacy/trusty

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.66-4ubuntu1
2.67-1
2.68-1
2.68-1ubuntu0.1
2.68-1ubuntu0.2
2.68-1ubuntu0.2+esm1
2.68-1ubuntu0.2+esm2
2.68-1ubuntu0.2+esm3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "dnsmasq",
            "binary_version": "2.68-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "dnsmasq-base",
            "binary_version": "2.68-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "dnsmasq-utils",
            "binary_version": "2.68-1ubuntu0.2+esm3"
        }
    ]
}

Ubuntu:16.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq@2.75-1ubuntu0.16.04.7?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.75-1ubuntu0.16.04.7

Affected versions

2.*

2.75-1
2.75-1ubuntu0.16.04.1
2.75-1ubuntu0.16.04.2
2.75-1ubuntu0.16.04.3
2.75-1ubuntu0.16.04.4
2.75-1ubuntu0.16.04.5

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "dnsmasq",
            "binary_version": "2.75-1ubuntu0.16.04.7"
        },
        {
            "binary_name": "dnsmasq-base",
            "binary_version": "2.75-1ubuntu0.16.04.7"
        },
        {
            "binary_name": "dnsmasq-utils",
            "binary_version": "2.75-1ubuntu0.16.04.7"
        }
    ]
}

Ubuntu:18.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq@2.79-1ubuntu0.2?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.79-1ubuntu0.2

Affected versions

2.*

2.78-1
2.78-3
2.79-1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "dnsmasq",
            "binary_version": "2.79-1ubuntu0.2"
        },
        {
            "binary_name": "dnsmasq-base",
            "binary_version": "2.79-1ubuntu0.2"
        },
        {
            "binary_name": "dnsmasq-base-lua",
            "binary_version": "2.79-1ubuntu0.2"
        },
        {
            "binary_name": "dnsmasq-utils",
            "binary_version": "2.79-1ubuntu0.2"
        }
    ]
}

Ubuntu:20.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq@2.80-1.1ubuntu1.2?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.80-1.1ubuntu1.2

Affected versions

2.*

2.80-1ubuntu2
2.80-1ubuntu4
2.80-1.1ubuntu1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "dnsmasq",
            "binary_version": "2.80-1.1ubuntu1.2"
        },
        {
            "binary_name": "dnsmasq-base",
            "binary_version": "2.80-1.1ubuntu1.2"
        },
        {
            "binary_name": "dnsmasq-base-lua",
            "binary_version": "2.80-1.1ubuntu1.2"
        },
        {
            "binary_name": "dnsmasq-utils",
            "binary_version": "2.80-1.1ubuntu1.2"
        }
    ]
}