{"id":"CVE-2019-18792","details":"An issue was discovered in Suricata 5.0.0. It is possible to bypass/evade any tcp based signature by overlapping a TCP segment with a fake FIN packet. The fake FIN packet is injected just before the PUSH ACK packet we want to bypass. The PUSH ACK packet (containing the data) will be ignored by Suricata because it overlaps the FIN packet (the sequence and ack number are identical in the two packets). The client will ignore the fake FIN packet because the ACK flag is not set. Both linux and windows clients are ignoring the injected packet.","modified":"2026-04-11T12:42:33.130530Z","published":"2020-01-06T18:15:23.183Z","references":[{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2020/01/msg00032.html"},{"type":"FIX","url":"https://github.com/OISF/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4b"},{"type":"FIX","url":"https://github.com/OISF/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006"},{"type":"EVIDENCE","url":"https://redmine.openinfosecfoundation.org/issues/3324"},{"type":"EVIDENCE","url":"https://redmine.openinfosecfoundation.org/issues/3394"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/oisf/suricata","events":[{"introduced":"45399567a65ea4ccbd84cee3638a1d2e61bdab4e"},{"fixed":"c91a7ad9dc3192c9c59c9d9a1f63131f1da4782e"},{"introduced":"0"},{"last_affected":"697410cbbfe351afd307424bab5590955a1b95ae"},{"introduced":"0"},{"last_affected":"9956286fb89f9cad9e9f95b99dc751f8666617b7"},{"fixed":"1c63d3905852f746ccde7e2585600b2199cefb4b"},{"fixed":"fa692df37a796c3330c81988d15ef1a219afc006"}],"database_specific":{"versions":[{"introduced":"4.1.5"},{"fixed":"4.1.6"},{"introduced":"0"},{"last_affected":"5.0.0"},{"introduced":"0"},{"last_affected":"8.0"}]}}],"versions":["suricata-0.8.2","suricata-1.0.0","suricata-1.0.1","suricata-1.0.2","suricata-1.1","suricata-1.1beta1","suricata-1.1beta2","suricata-1.1beta3","suricata-1.1rc1","suricata-1.2","suricata-1.2.1","suricata-1.2beta1","suricata-1.2rc1","suricata-1.3","suricata-1.3.1","suricata-1.3beta1","suricata-1.3beta2","suricata-1.3rc1","suricata-1.4","suricata-1.4beta1","suricata-1.4beta2","suricata-1.4beta3","suricata-1.4rc1","suricata-2.0","suricata-2.0.1","suricata-2.0.1rc1","suricata-2.0.2","suricata-2.0beta1","suricata-2.0beta2","suricata-2.0rc1","suricata-2.0rc2","suricata-2.0rc3","suricata-2.1beta1","suricata-2.1beta2","suricata-2.1beta3","suricata-2.1beta4","suricata-3.0","suricata-3.0.1","suricata-3.0.1RC1","suricata-3.0RC1","suricata-3.0RC2","suricata-3.0RC3","suricata-3.1","suricata-3.1.1","suricata-3.1.2","suricata-3.1RC1","suricata-3.2","suricata-3.2.1","suricata-3.2RC1","suricata-3.2beta1","suricata-4.0.0","suricata-4.0.0-beta1","suricata-4.0.0-rc1","suricata-4.0.0-rc2","suricata-4.0.1","suricata-4.1.0","suricata-4.1.0-beta1","suricata-4.1.0-rc1","suricata-4.1.0-rc2","suricata-4.1.1","suricata-4.1.2","suricata-4.1.5","suricata-5.0.0","suricata-5.0.0-beta1","suricata-5.0.0-rc1","suricata-5.0.1","suricata-6.0.0","suricata-6.0.0-beta1","suricata-6.0.0-rc1","suricata-6.0.1","suricata-7.0.0","suricata-7.0.0-beta1","suricata-7.0.0-rc1","suricata-7.0.0-rc2","suricata-7.0.1","suricata-7.0.2","suricata-8.0.0","suricata-8.0.0-beta1","suricata-8.0.0-rc1"],"database_specific":{"vanir_signatures_modified":"2026-04-11T12:42:33Z","vanir_signatures":[{"deprecated":false,"target":{"file":"src/stream-tcp.c"},"source":"https://github.com/oisf/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4b","signature_version":"v1","signature_type":"Line","id":"CVE-2019-18792-1a417d03","digest":{"threshold":0.9,"line_hashes":["308058807450816276028635852746118275748","221204083360005168731164196304212191593","21390434416426577672697603659514546199","241751286558114224891527998751973942008","315659100405804393893208892637684634774","7013461576087916721718213038207716288","51532122097456985586895166914441882440","46556905094042848375660928505030236932"]}},{"deprecated":false,"target":{"file":"src/stream-tcp.c"},"source":"https://github.com/oisf/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006","signature_version":"v1","signature_type":"Line","id":"CVE-2019-18792-2c67d5b3","digest":{"threshold":0.9,"line_hashes":["308058807450816276028635852746118275748","221204083360005168731164196304212191593","21390434416426577672697603659514546199","241751286558114224891527998751973942008","315659100405804393893208892637684634774","7013461576087916721718213038207716288","51532122097456985586895166914441882440","46556905094042848375660928505030236932"]}},{"deprecated":false,"target":{"file":"src/stream-tcp.c","function":"StreamTcpPacket"},"source":"https://github.com/oisf/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006","signature_version":"v1","signature_type":"Function","id":"CVE-2019-18792-63f7cd2e","digest":{"length":4675,"function_hash":"33221368742771496873975166895782756032"}},{"deprecated":false,"target":{"file":"src/stream-tcp.c","function":"StreamTcpTest10"},"source":"https://github.com/oisf/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4b","signature_version":"v1","signature_type":"Function","id":"CVE-2019-18792-c9346651","digest":{"length":2066,"function_hash":"186385305067634872466018488430576115100"}},{"deprecated":false,"target":{"file":"src/stream-tcp.c","function":"StreamTcpTest10"},"source":"https://github.com/oisf/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006","signature_version":"v1","signature_type":"Function","id":"CVE-2019-18792-d25a80a0","digest":{"length":2066,"function_hash":"186385305067634872466018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