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.
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