SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-18625

It was possible to bypass/evade any tcp based signature by faking a closed TCP session using an evil server.

HIGH 7.5EPSS 1.72%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.72%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An issue was discovered in Suricata 5.0.0. It was possible to bypass/evade any tcp based signature by faking a closed TCP session using an evil server. After the TCP SYN packet, it is possible to inject a RST ACK and a FIN ACK packet with a bad TCP Timestamp option. The client will ignore the RST ACK and the FIN ACK packets because of the bad TCP Timestamp option. Both linux and windows client are ignoring the injected packets.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
1.72% probability · 76th percentile
CISA KEV
Not listed
Affected
oisf/suricata · debian/debian linux
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.