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Vulnerability · Published Apr 8, 2021 · Assigned by redhat

CVE-2021-3448

Medium 4.0

In plain English

A medium-severity security flaw in dnsmasq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.3% (higher than 83% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.0Medium
Exploit odds (30 days)2.3%top 16.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8dnsmasq2.79-19.el8ALSA-2021:4153
AlmaLinux:8dnsmasq-utils2.79-19.el8ALSA-2021:4153
Alpine:v3.20dnsmasq2.85-r0ALPINE-CVE-2021-3448
Alpine:v3.21dnsmasq2.85-r0ALPINE-CVE-2021-3448
Alpine:v3.22dnsmasq2.85-r0ALPINE-CVE-2021-3448
Alpine:v3.23dnsmasq2.85-r0ALPINE-CVE-2021-3448
Alpine:v3.24dnsmasq2.85-r0ALPINE-CVE-2021-3448
Debian:12dnsmasq2.85-1DEBIAN-CVE-2021-3448
Debian:13dnsmasq2.85-1DEBIAN-CVE-2021-3448
Debian:14dnsmasq2.85-1DEBIAN-CVE-2021-3448
Rocky Linux:8dnsmasq0:2.79-19.el8RLSA-2021:4153

Affected products (as reported)

VendorProductVersions
n/a dnsmasq dnsmasq 2.85

Weakness: CWE-358 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N

References