Published

9 April 2019

Last modified

17 June 2026

CVSS

6.1 v3.1

Severity

medium

EPSS

0.6% (44th pct)

CISA KEV

Not listed

NVD status

Modified

Weaknesses

CWE-276

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

Description

A vulnerability was found in Samba from version (including) 4.9 to versions before 4.9.6 and 4.10.2. During the creation of a new Samba AD DC, files are created in a private subdirectory of the install location. This directory is typically mode 0700, that is owner (root) only access. However in some upgraded installations it will have other permissions, such as 0755, because this was the default before Samba 4.8. Within this directory, files are created with mode 0666, which is world-writable, including a sample krb5.conf, and the list of DNS names and servicePrincipalName values to update.

Exploitation

Not listed in the CISA Known Exploited Vulnerabilities catalogue as of 2026.09.04. That is an absence of confirmed public exploitation, not evidence that exploitation has not occurred. EPSS models a 0.6% probability of exploitation activity in the next 30 days.

Affected products

References

Vendor advisory and patch

• https://bugzilla.samba.org/show_bug.cgi?id=13834
• https://www.samba.org/samba/security/CVE-2019-3870.html
• https://bugzilla.samba.org/show_bug.cgi?id=13834
• https://www.samba.org/samba/security/CVE-2019-3870.html

• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3870 third-party
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6354GALK73CZWQKFUG7AWB6EIEGFMF62/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JTJVFA3RZ6G2IZDTVKLHRMX6QBYA4GPA/
• https://support.f5.com/csp/article/K20804356 third-party
• https://www.synology.com/security/advisory/Synology_SA_19_15 third-party
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3870 third-party
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6354GALK73CZWQKFUG7AWB6EIEGFMF62/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JTJVFA3RZ6G2IZDTVKLHRMX6QBYA4GPA/
• https://support.f5.com/csp/article/K20804356 third-party
• https://www.synology.com/security/advisory/Synology_SA_19_15 third-party

CVE-2019-3870 at NVD

Record assembled from NVD, CISA KEV 2026.09.04 and FIRST EPSS 2026-09-04. Affected products are those NVD's CPE configuration names that fall inside this site's scope; a CVE may affect products outside it.