CVE-2019-18792

NameCVE-2019-18792
DescriptionAn 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-2087-1, ELA-1162-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
suricata (PTS)jessie, jessie (lts)2.0.7-2+deb8u5fixed
stretch3.2.1-1+deb9u1vulnerable
buster, buster (lts)1:4.1.2-2+deb10u2fixed
bullseye1:6.0.1-3fixed
bookworm1:6.0.10-1fixed
sid, trixie1:7.0.8-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
suricatasourceexperimental1:5.0.1-1~exp1
suricatasourcejessie2.0.7-2+deb8u5DLA-2087-1
suricatasourcebuster1:4.1.2-2+deb10u2ELA-1162-1
suricatasource(unstable)1:5.0.2-1

Notes

[buster] - suricata <no-dsa> (Minor issue)
[stretch] - suricata <no-dsa> (Minor issue)
https://github.com/OISF/suricata/commit/1c63d3905852f746ccde7e2585600b2199cefb4b (master-4.1.x)
https://github.com/OISF/suricata/commit/fa692df37a796c3330c81988d15ef1a219afc006 (suricata-5.0.1)
https://redmine.openinfosecfoundation.org/issues/3324
https://redmine.openinfosecfoundation.org/issues/3394

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