CVE-2020-25686

Common vulnerabilities & exposures (CVE)

CVE database CVE database blogpost Release & EoL database

Published at: - 20-01-2021 06:15

Last modified: - 14-02-2022 04:29

Total changes: - 12

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.

Common Vulnerability Scoring System (CVSS)

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

High

Attack complexity

Network

Attack vector

None

Availability

None

Confidentiality

Low

Integrity

None

Privileges required

Unchanged

Scope

None

User interaction

3.7

Base score

2.2

1.4

Exploitability score

Impact score

Verification logic

vendor=thekelleys AND product=dnsmasq AND versionEndExcluding=2.83

vendor=fedoraproject AND product=fedora AND version=32

vendor=fedoraproject AND product=fedora AND version=33

vendor=Debian AND product=debian_linux AND version=10.0

vendor=arista AND product=eos AND versionStartIncluding=4.21 AND versionEndExcluding=4.21.14m

vendor=arista AND product=eos AND versionStartIncluding=4.22 AND versionEndExcluding=4.22.9m

vendor=arista AND product=eos AND versionStartIncluding=4.23 AND versionEndExcluding=4.23.7m

vendor=arista AND product=eos AND versionStartIncluding=4.24 AND versionEndExcluding=4.24.5m

vendor=arista AND product=eos AND versionStartIncluding=4.25 AND versionEndExcluding=4.25.2f

Reference

https://www.jsof-tech.com/disclosures/dnspooq/
https://bugzilla.redhat.com/show_bug.cgi?id=1890125
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
https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61

Keywords

CVE-2020-25686

Common vulnerabilities & exposures (CVE)

Description

Common Vulnerability Scoring System (CVSS)

Verification logic

Reference

NVD

CVE-2020-25686

CVE

Common vulnerabilities & exposures

CVSS

Common vulnerability scoring system

Security

Vulnerabilities

Exposures