CVE-2021-3448
MEDIUM4.0EPSS 0.04%Published: 4/8/2021Modified: 4/28/2026
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 (2)
- Alpine/dnsmasqfrom 0, < 2.85-r0
- Debian/dnsmasqfrom 0, < 2.85-1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N |