SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-25684

However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq.

LOW 3.7EPSS 4.04%

Does this matter?

Lower severity and a low EPSS score (4.04%). Track it; it rarely justifies an emergency change on its own.

Description

A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:reply_query() if the reply destination address/port is used by the pending forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.

CVSS 3.1
3.7 LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
4.04% probability · 90th percentile
CISA KEV
Not listed
Weakness
CWE-358
Affected
thekelleys/dnsmasq · fedoraproject/fedora · debian/debian linux · arista/eos
Source
secalert@redhat.com

References

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