CVE-2019-17455

Name: CVE-2019-17455
Creator: NVD / NIST
Published: 2019-10-10T18:15:11.647+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.11%

Last modified Jun 17, 2026

CVE-2019-17455 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Libntlm through 1.5 relies on a fixed buffer size for tSmbNtlmAuthRequest, tSmbNtlmAuthChallenge, and tSmbNtlmAuthResponse read and write operations, as demonstrated by a stack-based buffer over-read in buildSmbNtlmAuthRequest in smbutil.c for a crafted NTLM request.. EPSS estimates a 3.11% chance of exploitation in the next 30 days.

Description

Libntlm through 1.5 relies on a fixed buffer size for tSmbNtlmAuthRequest, tSmbNtlmAuthChallenge, and tSmbNtlmAuthResponse read and write operations, as demonstrated by a stack-based buffer over-read in buildSmbNtlmAuthRequest in smbutil.c for a crafted NTLM request.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

3.11%

86.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions	Update
Nongnu	Libntlm	<= 1.5	—
Debian	Debian Linux	8.0	—
Debian	Debian Linux	9.0	—
Canonical	Ubuntu Linux	14.04	—
Canonical	Ubuntu Linux	16.04	—
Canonical	Ubuntu Linux	18.04	—
Canonical	Ubuntu Linux	20.04	—
Fedoraproject	Fedora	32	—
Fedoraproject	Fedora	33	—
Opensuse	Backports Sle	15.0	Sp1
Opensuse	Leap	15.1	—

References

http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00029.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00032.htmlMailing List, Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=942145Exploit, Issue Tracking, Mailing List, Third Party Advisory
https://gitlab.com/jas/libntlm/issues/2Exploit, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/05/msg00010.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00026.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3BVFO3OVJPMSGIXBKNOCVOJZ3UTGZQF5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YZ5YWYNOJ5HMCKAHWLTY4MXZQWJJCBI7/
https://people.canonical.com/~ubuntu-security/cve/2019/CVE-2019-17455.htmlThird Party Advisory
https://security-tracker.debian.org/tracker/CVE-2019-17455Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00029.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00032.htmlMailing List, Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=942145Exploit, Issue Tracking, Mailing List, Third Party Advisory
https://gitlab.com/jas/libntlm/issues/2Exploit, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/05/msg00010.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/11/msg00026.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3BVFO3OVJPMSGIXBKNOCVOJZ3UTGZQF5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YZ5YWYNOJ5HMCKAHWLTY4MXZQWJJCBI7/
https://people.canonical.com/~ubuntu-security/cve/2019/CVE-2019-17455.htmlThird Party Advisory
https://security-tracker.debian.org/tracker/CVE-2019-17455Third Party Advisory

Timeline

Published: Oct 10, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-17455?

How severe is CVE-2019-17455?

CVE-2019-17455 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.11% probability of exploitation in the next 30 days.

How do I fix CVE-2019-17455?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-17455?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST