{"id":"CVE-2020-25683","details":"A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in get_rdata() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.","modified":"2026-04-16T04:37:11.584468327Z","published":"2021-01-20T16:15:14.087Z","related":["SUSE-SU-2021:0162-1","SUSE-SU-2021:0163-1","SUSE-SU-2021:0166-1","SUSE-SU-2021:14603-1","SUSE-SU-2021:14604-1","openSUSE-SU-2021:0124-1","openSUSE-SU-2021:0129-1","openSUSE-SU-2024:10721-1"],"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/"},{"type":"WEB","url":"https://www.kb.cert.org/vuls/id/434904"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202101-17"},{"type":"ADVISORY","url":"https://www.debian.org/security/2021/dsa-4844"},{"type":"ADVISORY","url":"https://www.jsof-tech.com/disclosures/dnspooq/"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html"},{"type":"FIX","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1882018"}],"affected":[{"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"0"},{"fixed":"2.83"}]},{"events":[{"introduced":"0"},{"last_affected":"32"}]},{"events":[{"introduced":"0"},{"last_affected":"33"}]},{"events":[{"introduced":"0"},{"last_affected":"9.0"}]},{"events":[{"introduced":"0"},{"last_affected":"10.0"}]},{"events":[{"introduced":"0"},{"fixed":"2.83"}]}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-25683.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}