CVE-2021-3448

low-risk
Published 2021-04-08

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.

Do I need to act?

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0.04% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
4
CVSS 4.0/10 Medium
NETWORK / HIGH complexity
26
/ 100
low-risk
Severity 13/34 · Low
Exploitability 0/34 · Minimal
Exposure 13/34 · Low