{"id":"ALPINE-CVE-2020-25685","details":"A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. 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":"2026-08-20T10:18:02.623028951Z","published":"2021-01-20T16:15:14.303Z","upstream":["CVE-2020-25685"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2020-25685"}],"affected":[{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.10","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.11","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.12","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.13","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.14","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/dnsmasq?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.83-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2020-25685.json"}},{"package":{"name":"dnsmasq","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/dnsmasq?arch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