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Ubuntu: (Multiple Advisories) (CVE-2020-25686): Dnsmasq vulnerabilities

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Ubuntu: (Multiple Advisories) (CVE-2020-25686): Dnsmasq vulnerabilities

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:P/A:N)
Published
01/19/2021
Created
01/22/2021
Added
01/20/2021
Modified
03/22/2023

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.

Solution(s)

  • ubuntu-upgrade-dnsmasq
  • ubuntu-upgrade-dnsmasq-base
  • ubuntu-upgrade-dnsmasq-utils

References

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