UBUNTU-CVE-2020-25685

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Source
https://ubuntu.com/security/CVE-2020-25685
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-25685.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2020-25685
Related
Published
2021-01-19T00:00:00Z
Modified
2024-10-15T14:07:39Z
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
Summary
[none]
Details

A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25684 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?arch=src?distro=trusty/esm

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

Ecosystem specific 

{
    "ubuntu_priority": "medium"
}

Ubuntu:16.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq?arch=src?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",
    "ubuntu_priority": "medium",
    "binaries": [
        {
            "binary_version": "2.75-1ubuntu0.16.04.7",
            "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"
        }
    ]
}

Ubuntu:18.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq?arch=src?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",
    "ubuntu_priority": "medium",
    "binaries": [
        {
            "binary_version": "2.79-1ubuntu0.2",
            "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"
        }
    ]
}

Ubuntu:20.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq?arch=src?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",
    "ubuntu_priority": "medium",
    "binaries": [
        {
            "binary_version": "2.80-1.1ubuntu1.2",
            "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"
        }
    ]
}