CVE-2021-3448

Name: CVE-2021-3448
Creator: NVD / NIST
Published: 2021-04-08T23:15:12.597+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4/10EPSS 1.99%

Last modified Jun 17, 2026

CVE-2021-3448 is a medium-severity vulnerability rated 4/10 on the CVSS scale. A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. EPSS estimates a 1.99% chance of exploitation in the next 30 days.

Description

A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity.

Metrics

CVSS 3.1

4/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N

EPSS Probability

1.99%

78.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-358

Affected Software

Vendor	Product	Versions
Thekelleys	Dnsmasq	< 2.85
Redhat	Enterprise Linux	8.0
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34
Oracle	Communications Cloud Native Core Network Function Cloud Native Environment	1.9.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1939368Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CVTJUOFFFHINLKWAOC2ZSC5MOPD4SJ24/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHG7GWSQWKF7JXIMLOGJBKZWBB4VIAJ7/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GHURNEHHUBSW45KMIZ4FNBCSUPWPGV5V/
https://security.gentoo.org/glsa/202105-20Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1939368Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CVTJUOFFFHINLKWAOC2ZSC5MOPD4SJ24/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHG7GWSQWKF7JXIMLOGJBKZWBB4VIAJ7/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GHURNEHHUBSW45KMIZ4FNBCSUPWPGV5V/
https://security.gentoo.org/glsa/202105-20Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.htmlPatch, Third Party Advisory

Timeline

Published: Apr 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3448?

How severe is CVE-2021-3448?

CVE-2021-3448 has a CVSS score of 4/10 (MEDIUM severity). The EPSS model estimates a 1.99% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3448?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3448?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST