What is CVE-2019-17420?

CVE-2019-17420 is a medium-severity vulnerability in Oisf Libhtp, classified under Incomplete Cleanup. CVSS score: 5.3/10. Published 2019-10-10.

How severe is CVE-2019-17420?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Oisf Libhtp

CVE-2019-17420

In OISF LibHTP before 0.5.31, as used in Suricata 4.1.4 and other products, an HTTP protocol parsing error causes the http_header signature to not alert on a response with a single \r\n ending.

Published 2019-10-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.014 (70.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 70.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

Oisf Libhtp
Suricata-Ids Suricata — versions 4.1.4

Weakness classification (CWE)

CWE-459 — Incomplete Cleanup

References

redmine.openinfosecfoundation.org/issues/2969 (Issue Tracking, Vendor Advisory)
github.com/OISF/libhtp/compare/0.5.30...0.5.31 (Patch)
github.com/OISF/libhtp/pull/213 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2019-17420?: CVE-2019-17420 is a medium-severity vulnerability in Oisf Libhtp, classified under Incomplete Cleanup. CVSS score: 5.3/10. Published 2019-10-10.
How severe is CVE-2019-17420?: Medium severity. CVSS v3 base score is 5.3 out of 10.