CVE-2020-25686

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
20/01/2021
Last modified:
07/11/2023

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.

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:thekelleys:dnsmasq:*:*:*:*:*:*:*:* 2.83 (excluding)
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 4.21 (including) 4.21.14m (excluding)
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 4.22 (including) 4.22.9m (excluding)
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 4.23 (including) 4.23.7m (excluding)
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 4.24 (including) 4.24.5m (excluding)
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 4.25 (including) 4.25.2f (excluding)