USN-4976-1

See a problem?
Please try reporting it to the source first.
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.osv.dev/v1/vulns/USN-4976-1
Upstream
Related
Published
2021-06-02T13:21:40Z
Modified
2026-02-10T04:42:13Z
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_version": "2.79-1ubuntu0.4",
            "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"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2021-3448",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:18.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4976-1.json"

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_version": "2.80-1.1ubuntu1.4",
            "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"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2021-3448",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "low",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:20.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-4976-1.json"