CVE catalog

CVE-2021-3448

dnsmasq: CVE-2021-3448

Severity: Medium · CVSS 4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
Published: Apr 8, 2021, 11:15:00 PM UTC
Source: [NVD] · [CVE record]
EPSS: 2.28% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	dnsmasq	sid	`2.93-3`	fixed
Debian	dnsmasq	forky	`2.93-3`	fixed
Debian	dnsmasq	trixie	`2.91-1+deb13u2`	fixed
Debian	dnsmasq	trixie-security	`2.91-1+deb13u1`	fixed
Debian	dnsmasq	bookworm	`2.90-4~deb12u2`	fixed
Debian	dnsmasq	bookworm-security	`2.90-4~deb12u2`	fixed
Alpine	dnsmasq	3.10	`2.85-r0`	fixed
Alpine	dnsmasq	3.11	`2.85-r0`	fixed
Alpine	dnsmasq	3.12	`2.85-r0`	fixed
Alpine	dnsmasq	3.13	`2.85-r0`	fixed
Alpine	dnsmasq	3.14	`2.85-r0`	fixed
Alpine	dnsmasq	3.15	`2.85-r0`	fixed
Alpine	dnsmasq	3.16	`2.85-r0`	fixed
Alpine	dnsmasq	3.17	`2.85-r0`	fixed
Alpine	dnsmasq	3.18	`2.85-r0`	fixed
Alpine	dnsmasq	3.19	`2.85-r0`	fixed
Alpine	dnsmasq	3.20	`2.85-r0`	fixed
Alpine	dnsmasq	3.21	`2.85-r0`	fixed
Alpine	dnsmasq	3.22	`2.85-r0`	fixed
Alpine	dnsmasq	3.23	`2.85-r0`	fixed
Alpine	dnsmasq	3.24	`2.85-r0`	fixed
Ubuntu	dnsmasq	pro	`2.75-1`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.1`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.2`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.3`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.4`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.5`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.7`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.8`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.10`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.10+esm1`	vulnerable
Ubuntu	dnsmasq	pro	`2.79-1ubuntu0.16.04.1+esm1`	fixed
Ubuntu	dnsmasq	pro	`2.75-1`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.1`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.2`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.3`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.4`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.5`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.7`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.8`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.10`	vulnerable
Ubuntu	dnsmasq	pro	`2.75-1ubuntu0.16.04.10+esm1`	vulnerable
Ubuntu	dnsmasq	pro	`2.79-1ubuntu0.16.04.1+esm1`	fixed
Ubuntu	dnsmasq	18.04	`2.78-1`	vulnerable
Ubuntu	dnsmasq	18.04	`2.78-3`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1ubuntu0.2`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1ubuntu0.3`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1ubuntu0.4`	fixed
Ubuntu	dnsmasq	20.04	`2.80-1ubuntu2`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1ubuntu4`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1.2`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1.3`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1.4`	fixed
Ubuntu	dnsmasq	18.04	`2.78-1`	vulnerable
Ubuntu	dnsmasq	18.04	`2.78-3`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1ubuntu0.2`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1ubuntu0.3`	vulnerable
Ubuntu	dnsmasq	18.04	`2.79-1ubuntu0.4`	fixed
Ubuntu	dnsmasq	20.04	`2.80-1ubuntu2`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1ubuntu4`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1.2`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1.3`	vulnerable
Ubuntu	dnsmasq	20.04	`2.80-1.1ubuntu1.4`	fixed
Suse	dnsmasq	linux enterprise server 11 sp4-ltss	`2.78-0.17.18.1`	fixed
Suse	dnsmasq	linux enterprise high performance computing 15-espos	`2.78-150000.3.14.1`	fixed
Suse	dnsmasq	linux enterprise high performance computing 15-ltss	`2.78-150000.3.14.1`	fixed
Suse	dnsmasq	linux enterprise server 15-ltss	`2.78-150000.3.14.1`	fixed
Suse	dnsmasq	linux enterprise server for sap applications 15	`2.78-150000.3.14.1`	fixed
Suse	dnsmasq	hpe helion openstack 8	`2.78-18.18.1`	fixed
Suse	dnsmasq	openstack cloud 8	`2.78-18.18.1`	fixed
Suse	dnsmasq	openstack cloud 9	`2.78-18.18.1`	fixed
Suse	dnsmasq	openstack cloud crowbar 8	`2.78-18.18.1`	fixed
Suse	dnsmasq	openstack cloud crowbar 9	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server for sap applications 12 sp3	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server for sap applications 12 sp4	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server 12 sp2-bcl	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server 12 sp3-ltss	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server 12 sp3-bcl	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server 12 sp4-ltss	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server 12 sp5	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise server for sap applications 12 sp5	`2.78-18.18.1`	fixed
Suse	dnsmasq	linux enterprise point of sale 11 sp3	`2.78-0.16.17.1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	dnsmasq	source	sid	`2.85-1`	not yet assigned	Not reported	Not reported
Debian	dnsmasq	source	forky	`2.85-1`	not yet assigned	Not reported	Not reported
Debian	dnsmasq	source	trixie	`2.85-1`	not yet assigned	Not reported	Not reported
Debian	dnsmasq	source	bookworm	`2.85-1`	not yet assigned	Not reported	Not reported
Alpine	dnsmasq	apk	3.10	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.11	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.12	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.13	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.14	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.15	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.16	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.17	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.18	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.19	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.20	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.21	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.22	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.23	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Alpine	dnsmasq	apk	3.24	`2.85-r0`	Not reported	ALPINE-CVE-2021-3448	Not reported
Ubuntu	dnsmasq	deb	pro	`2.79-1ubuntu0.16.04.1+esm1`	Not reported	USN-4976-2	Not reported
Ubuntu	dnsmasq	deb	pro	`2.79-1ubuntu0.16.04.1+esm1`	Not reported	UBUNTU-CVE-2021-3448	Not reported
Ubuntu	dnsmasq	deb	18.04	`2.79-1ubuntu0.4`	Not reported	UBUNTU-CVE-2021-3448	Not reported
Ubuntu	dnsmasq	deb	20.04	`2.80-1.1ubuntu1.4`	Not reported	UBUNTU-CVE-2021-3448	Not reported
Ubuntu	dnsmasq	deb	18.04	`2.79-1ubuntu0.4`	Not reported	USN-4976-1	Not reported
Ubuntu	dnsmasq	deb	20.04	`2.80-1.1ubuntu1.4`	Not reported	USN-4976-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server 11 sp4-ltss	`2.78-0.17.18.1`	Not reported	SUSE-SU-2022:14941-1	Not reported
Suse	dnsmasq	rpm	linux enterprise high performance computing 15-espos	`2.78-150000.3.14.1`	Not reported	SUSE-SU-2022:1288-1	Not reported
Suse	dnsmasq	rpm	linux enterprise high performance computing 15-ltss	`2.78-150000.3.14.1`	Not reported	SUSE-SU-2022:1288-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server 15-ltss	`2.78-150000.3.14.1`	Not reported	SUSE-SU-2022:1288-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server for sap applications 15	`2.78-150000.3.14.1`	Not reported	SUSE-SU-2022:1288-1	Not reported
Suse	dnsmasq	rpm	hpe helion openstack 8	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	openstack cloud 8	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	openstack cloud 9	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	openstack cloud crowbar 8	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	openstack cloud crowbar 9	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server for sap applications 12 sp3	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server for sap applications 12 sp4	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server 12 sp2-bcl	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server 12 sp3-ltss	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server 12 sp3-bcl	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server 12 sp4-ltss	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server 12 sp5	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise server for sap applications 12 sp5	`2.78-18.18.1`	Not reported	SUSE-SU-2022:1289-1	Not reported
Suse	dnsmasq	rpm	linux enterprise point of sale 11 sp3	`2.78-0.16.17.1`	Not reported	SUSE-SU-2022:14940-1	Not reported

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[dnsmasq]Unknown
Details (4)
- 2.90-4~deb12u2 · all · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · all · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · all · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · all · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
[dnsmasq-base]Unknown
Source package: [dnsmasq]
Details (4)
- 2.90-4~deb12u2 · amd64 · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · arm64 · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · amd64 · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · arm64 · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
[dnsmasq-base-lua]Unknown
Source package: [dnsmasq]
Details (4)
- 2.90-4~deb12u2 · amd64 · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · arm64 · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · amd64 · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · arm64 · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
[dnsmasq-utils]Unknown
Source package: [dnsmasq]
Details (4)
- 2.90-4~deb12u2 · amd64 · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · arm64 · bookworm
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · amd64 · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- 2.90-4~deb12u2 · arm64 · bookworm-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12

[Debian 13 (Trixie)]

[dnsmasq]Unknown
Details (4)
- 2.91-1+deb13u1 · all · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · all · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · all · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · all · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
[dnsmasq-base]Unknown
Source package: [dnsmasq]
Details (4)
- 2.91-1+deb13u1 · amd64 · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · arm64 · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · arm64 · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
[dnsmasq-base-lua]Unknown
Source package: [dnsmasq]
Details (4)
- 2.91-1+deb13u1 · amd64 · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · arm64 · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · arm64 · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
[dnsmasq-utils]Unknown
Source package: [dnsmasq]
Details (4)
- 2.91-1+deb13u1 · amd64 · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · arm64 · trixie
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13
- 2.91-1+deb13u1 · arm64 · trixie-security
  Fixed · Fixed: 2.85-1
  dsa · dnsmasq · debian · 13

Observed: Oct 23, 2026, 5:58:10 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]