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.
NOTE: The following CVSS v3.0 metrics and score provided are preliminary and subject to review.
|Base Score:||3.7||Base Metrics:||AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N|
|Access Vector:||Network||Attack Complexity:||High|
|Privileges Required:||None||User Interaction:||None|
|Integrity Impact:||Low||Availability Impact:||None|
|Oracle Linux version 7 (dnsmasq)||ELSA-2021-0153||2021-01-19|
|Oracle Linux version 8 (dnsmasq)||ELSA-2021-0150||2021-01-20|
This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections please contact the Oracle Linux ULN team