CVE-2020-25684

 

Published at: - 20-01-2021 05:15

Last modified: - 14-02-2022 03:56

Total changes: - 15

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.

Common Vulnerability Scoring System (CVSS)

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

 

Verification logic

 

Reference

• https://bugzilla.redhat.com/show_bug.cgi?id=1889686
• https://www.jsof-tech.com/disclosures/dnspooq/
• FEDORA-2021-84440e87ba-Mailing List, Third Party Advisory
• GLSA-202101-17-Third Party Advisory
• DSA-4844-Third Party Advisory
• FEDORA-2021-2e4c3d5a9d-Mailing List, Third Party Advisory
• [debian-lts-announce] 20210322 [SECURITY] [DLA 2604-1] dnsmasq security update-Mailing List, Third Party Advisory
• https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61

 

Keywords

NVD

 

CVE-2020-25684

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures