CVE-2023-3347

Name: CVE-2023-3347
Creator: NVD / NIST
Published: 2023-07-20T15:15:11.94+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.9/10EPSS 0.39%

Last modified Jun 17, 2026

CVE-2023-3347 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. A vulnerability was found in Samba's SMB2 packet signing mechanism. The SMB2 packet signing is not enforced if an admin configured "server signing = required" or for SMB2 connections to Domain Controllers where SMB2 packet signing is mandatory. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

A vulnerability was found in Samba's SMB2 packet signing mechanism. The SMB2 packet signing is not enforced if an admin configured "server signing = required" or for SMB2 connections to Domain Controllers where SMB2 packet signing is mandatory. This flaw allows an attacker to perform attacks, such as a man-in-the-middle attack, by intercepting the network traffic and modifying the SMB2 messages between client and server, affecting the integrity of the data.

Metrics

CVSS 3.1

5.9/10

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

EPSS Probability

0.39%

30.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Samba	Samba	>= 4.17.0, < 4.17.10
Samba	Samba	>= 4.18.0, < 4.18.5
Redhat	Storage	3.0
Redhat	Enterprise Linux	8.0
Redhat	Enterprise Linux	9.0
Fedoraproject	Fedora	38

References

https://access.redhat.com/errata/RHSA-2023:4325Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:4328Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-3347Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2222792Issue Tracking, Third Party Advisory
https://www.samba.org/samba/security/CVE-2023-3347.htmlVendor Advisory
https://access.redhat.com/errata/RHSA-2023:4325Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:4328Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-3347Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2222792Issue Tracking, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BPCSGND7LO467AJGR5DYBGZLTCGTOBCC/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OT74M42E6C36W7PQVY3OS4ZM7DVYB64Z/
https://security.netapp.com/advisory/ntap-20230731-0010/
https://www.debian.org/security/2023/dsa-5477
https://www.samba.org/samba/security/CVE-2023-3347.htmlVendor Advisory

Timeline

Published: Jul 20, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-3347?

How severe is CVE-2023-3347?

CVE-2023-3347 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.

How do I fix CVE-2023-3347?

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-2023-3347?

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

Scan your code now

Source: NVD / NIST