SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-3448

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.

MEDIUM 4.0EPSS 2.29%

Does this matter?

Lower severity and a low EPSS score (2.29%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
4.0 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N
EPSS
2.29% probability · 82th percentile
CISA KEV
Not listed
Weakness
CWE-358
Affected
thekelleys/dnsmasq · redhat/enterprise linux · fedoraproject/fedora · oracle/communications cloud native core network function cloud native environment
Source
secalert@redhat.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.