CVE-2020-25686

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.

• thekelleys dnsmasq (< 2.83) • fedoraproject fedora 32 • fedoraproject fedora 33 • debian debian linux 10.0 • arista eos (>= 4.21 < 4.21.14m) • arista eos (>= 4.22 < 4.22.9m) • arista eos (>= 4.23 < 4.23.7m) • arista eos (>= 4.24 < 4.24.5m) • arista eos (>= 4.25 < 4.25.2f)