CVE-2020-25686

LowCVSS 3.7/10Last modified Jun 17, 2026

Description

A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the "Birthday Attacks" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.

Metrics

CVSS 3.1 3.7/10CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Weakness enumeration

CWE-358 CWE-290

Affected software

No affected versions have been published.

Timeline

Published: Jan 20, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2020

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