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.
References
Link | Resource |
---|---|
https://github.com/OISF/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4b | Patch Third Party Advisory |
https://github.com/OISF/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006 | Patch Third Party Advisory |
https://lists.debian.org/debian-lts-announce/2020/01/msg00032.html | Third Party Advisory |
https://redmine.openinfosecfoundation.org/issues/3324 | Exploit Third Party Advisory |
https://redmine.openinfosecfoundation.org/issues/3394 | Exploit Third Party Advisory |
History
No history.
MITRE Information
Status: PUBLISHED
Assigner: mitre
Published: 2020-01-06T17:52:54
Updated: 2020-01-30T17:06:09
Reserved: 2019-11-06T00:00:00
Link: CVE-2019-18792
JSON object: View
NVD Information
Status : Analyzed
Published: 2020-01-06T18:15:23.183
Modified: 2021-07-21T11:39:23.747
Link: CVE-2019-18792
JSON object: View
Redhat Information
No data.
CWE