USN-4976-1

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Source
https://ubuntu.com/security/notices/USN-4976-1
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4976-1.json
JSON Data
https://api.test.osv.dev/v1/vulns/USN-4976-1
Upstream
Related
Published
2021-06-02T13:21:40.124016Z
Modified
2025-07-16T08:54:55.579506Z
Summary
dnsmasq vulnerability
Details

Petr Mensik discovered that Dnsmasq incorrectly randomized source ports in certain configurations. A remote attacker could possibly use this issue to facilitate DNS cache poisoning attacks.

References

Affected packages

Ubuntu:18.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq@2.79-1ubuntu0.4?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.79-1ubuntu0.4

Affected versions

2.*

2.78-1
2.78-3
2.79-1
2.79-1ubuntu0.2
2.79-1ubuntu0.3

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "dnsmasq",
            "binary_version": "2.79-1ubuntu0.4"
        },
        {
            "binary_name": "dnsmasq-base",
            "binary_version": "2.79-1ubuntu0.4"
        },
        {
            "binary_name": "dnsmasq-base-lua",
            "binary_version": "2.79-1ubuntu0.4"
        },
        {
            "binary_name": "dnsmasq-utils",
            "binary_version": "2.79-1ubuntu0.4"
        }
    ]
}

Ubuntu:20.04:LTS / dnsmasq

Package

Name
dnsmasq
Purl
pkg:deb/ubuntu/dnsmasq@2.80-1.1ubuntu1.4?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.80-1.1ubuntu1.4

Affected versions

2.*

2.80-1ubuntu2
2.80-1ubuntu4
2.80-1.1ubuntu1
2.80-1.1ubuntu1.2
2.80-1.1ubuntu1.3

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "dnsmasq",
            "binary_version": "2.80-1.1ubuntu1.4"
        },
        {
            "binary_name": "dnsmasq-base",
            "binary_version": "2.80-1.1ubuntu1.4"
        },
        {
            "binary_name": "dnsmasq-base-lua",
            "binary_version": "2.80-1.1ubuntu1.4"
        },
        {
            "binary_name": "dnsmasq-utils",
            "binary_version": "2.80-1.1ubuntu1.4"
        }
    ]
}