CVE-2019-19977

Name: CVE-2019-19977
Creator: NVD / NIST
Published: 2019-12-26T01:15:10.973+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.06%

Last modified Jun 17, 2026

CVE-2019-19977 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. libESMTP through 1.0.6 mishandles domain copying into a fixed-size buffer in ntlm_build_type_2 in ntlm/ntlmstruct.c, as demonstrated by a stack-based buffer over-read.. EPSS estimates a 3.06% chance of exploitation in the next 30 days.

Description

libESMTP through 1.0.6 mishandles domain copying into a fixed-size buffer in ntlm_build_type_2 in ntlm/ntlmstruct.c, as demonstrated by a stack-based buffer over-read.

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

3.06%

85.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

Affected Software

Vendor	Product	Versions
Libesmtp Project	Libesmtp	<= 1.0.6

References

https://github.com/Kirin-say/Vulnerabilities/blob/master/Stack_Overflow_in_libesmtp.mdExploit, Patch, Third Party Advisory
https://github.com/jbouse-debian/libesmtp/blob/ca5bd0800ef1da234315da4c59716568eb5e6402/ntlm/ntlmstruct.c#L228-L242Exploit, Third Party Advisory
https://web.archive.org/web/20190528215510/http://brianstafford.info/libesmtp/Product
https://github.com/Kirin-say/Vulnerabilities/blob/master/Stack_Overflow_in_libesmtp.mdExploit, Patch, Third Party Advisory
https://github.com/jbouse-debian/libesmtp/blob/ca5bd0800ef1da234315da4c59716568eb5e6402/ntlm/ntlmstruct.c#L228-L242Exploit, Third Party Advisory
https://web.archive.org/web/20190528215510/http://brianstafford.info/libesmtp/Product

Timeline

Published: Dec 26, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-19977?

libESMTP through 1.0.6 mishandles domain copying into a fixed-size buffer in ntlm_build_type_2 in ntlm/ntlmstruct.c, as demonstrated by a stack-based buffer over-read.

How severe is CVE-2019-19977?

CVE-2019-19977 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.06% probability of exploitation in the next 30 days.

How do I fix CVE-2019-19977?

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-2019-19977?

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

Scan your code now

Source: NVD / NIST