{"id":"CVE-2020-35680","details":"smtpd/lka_filter.c in OpenSMTPD before 6.8.0p1, in certain configurations, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted pattern of client activity, because the filter state machine does not properly maintain the I/O channel between the SMTP engine and the filters layer.","modified":"2026-07-09T00:22:05.779697Z","published":"2020-12-24T16:15:15.600Z","database_specific":{"unresolved_ranges":[{"extracted_events":[{"fixed":"6.8.0"}],"source":"CPE_RANGE","vendor_product":"opensmtpd:opensmtpd","cpes":["cpe:2.3:a:opensmtpd:opensmtpd:*:*:*:*:*:*:*:*"]},{"source":"CPE_STRING","vendor_product":"fedoraproject:fedora","cpes":["cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*","cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"32"},{"last_affected":"32"},{"introduced":"33"},{"last_affected":"33"}]},{"source":"CPE_STRING","vendor_product":"opensmtpd:opensmtpd","cpes":["cpe:2.3:a:opensmtpd:opensmtpd:6.8.0:-:*:*:*:*:*:*"],"extracted_events":[{"introduced":"6.8.0-NA"},{"last_affected":"6.8.0-NA"}]}]},"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/"},{"type":"WEB","url":"https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html"},{"type":"ADVISORY","url":"https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202105-12"},{"type":"FIX","url":"https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openbsd/src","events":[{"introduced":"0"},{"fixed":"6c3220444ed06b5796dedfd53a0f4becd903c0d1"}],"database_specific":{"source":"REFERENCES"}}],"database_specific":{"vanir_signatures_modified":"2026-07-09T00:22:05Z","vanir_signatures":[{"deprecated":false,"digest":{"line_hashes":["146958479146620846539546414962359749417","331739472224798831840993251905507474107","91893901251692159920292890227734731430","279425024596136944150789901713018609996","302454195925576915379956718349724179184","102226086405913718666762852662536102668","156377891668464352413748805278213613186","294224973442606065565798747585475670296"],"threshold":0.9},"id":"CVE-2020-35680-5a2407e5","signature_type":"Line","signature_version":"v1","source":"https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1","target":{"file":"usr.sbin/smtpd/lka_filter.c"}},{"deprecated":false,"digest":{"function_hash":"139574854378595409949297631104406793897","length":477},"id":"CVE-2020-35680-e9b83694","signature_type":"Function","signature_version":"v1","source":"https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1","target":{"file":"usr.sbin/smtpd/lka_filter.c","function":"filter_session_io"}}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-35680.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/opensmtpd/opensmtpd","events":[{"introduced":"b9e207ab4e42dff36a56e0b32d67f5c50e4f63fb"},{"last_affected":"b9e207ab4e42dff36a56e0b32d67f5c50e4f63fb"}],"database_specific":{"cpe":"cpe:2.3:a:opensmtpd:opensmtpd:6.8.0:patch1-rc1:*:*:*:*:*:*","extracted_events":[{"introduced":"6.8.0-patch1\\-rc1"},{"last_affected":"6.8.0-patch1\\-rc1"}],"source":"CPE_STRING"}}],"versions":["6.8.0-patch1\\-rc1","opensmtpd-6.8.0p1-rc1","6.8.0p1-rc1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-35680.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}