{"id":"DEBIAN-CVE-2020-25686","details":"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.","modified":"2026-09-01T16:04:59.861342912Z","published":"2021-01-20T17:15:13Z","upstream":["CVE-2020-25686"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2020-25686"}],"affected":[{"package":{"name":"dnsmasq","ecosystem":"Debian:12","purl":"pkg:deb/debian/dnsmasq?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-25686.json"}},{"package":{"name":"dnsmasq","ecosystem":"Debian:13","purl":"pkg:deb/debian/dnsmasq?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-25686.json"}},{"package":{"name":"dnsmasq","ecosystem":"Debian:14","purl":"pkg:deb/debian/dnsmasq?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-25686.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N"}]}