Samba: smb2 packet signing is not enforced when "server signing = required" is set
Priority LOW 27CWE-347Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 7 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-347.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00436 38th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 7 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 8 | — | 4.17.5-3.el8_8 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | 4.17.5-3.el8_8 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 4.17.5-103.el9_2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 4.17.5-103.el9_2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Storage 3 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 4.17.5-3.el8_8 Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 4.17.5-3.el8_8 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 4.17.5-103.el9_2 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 4.17.5-103.el9_2 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Storage 3 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:* | 4.17.0 to before 4.17.10; 4.18.0 to before 4.18.5 | Vulnerable | Samba |
| cpe:2.3:a:redhat:storage:3.0:*:*:*:*:*:*:* | 3.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Red Hat |
| cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:* | 38 | Vulnerable | Fedoraproject |
- cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:* Versions 4.17.0 to before 4.17.10; 4.18.0 to before 4.18.5 Vulnerable ·Samba
- cpe:2.3:a:redhat:storage:3.0:*:*:*:*:*:*:* Versions 3.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
- cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:* Versions 38 Vulnerable ·Fedoraproject
Remediation
Red Hat 2 advisories
- RHSA-2023:4328 Released 2023-07-31 · Red Hat rating Moderatesamba security and bug fix update
- Red Hat Enterprise Linux AppStream (v. 8) samba-vfs-iouring-4.17.5-3.el8_8
- Red Hat Enterprise Linux BaseOS (v. 8) ctdb-4.17.5-3.el8_8, libnetapi-4.17.5-3.el8_8, libsmbclient-4.17.5-3.el8_8 +25
- Red Hat Enterprise Linux CRB (v. 8) libnetapi-devel-4.17.5-3.el8_8, libsmbclient-devel-4.17.5-3.el8_8, libwbclient-devel-4.17.5-3.el8_8 +2
- RHSA-2023:4325 Released 2023-07-31 · Red Hat rating Moderatesamba security and bug fix update
- Red Hat Enterprise Linux AppStream (v. 9) samba-client-4.17.5-103.el9_2, samba-krb5-printing-4.17.5-103.el9_2, samba-vfs-iouring-4.17.5-103.el9_2 +3
- Red Hat Enterprise Linux BaseOS (v. 9) libnetapi-4.17.5-103.el9_2, libsmbclient-4.17.5-103.el9_2, libwbclient-4.17.5-103.el9_2 +15
- Red Hat Enterprise Linux CRB (v. 9) libnetapi-devel-4.17.5-103.el9_2, libsmbclient-devel-4.17.5-103.el9_2, libwbclient-devel-4.17.5-103.el9_2 +6
- Red Hat Enterprise Linux ResilientStorage (v. 9) ctdb-4.17.5-103.el9_2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Storage 3 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2023:4328 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2023:4325 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2023:4328 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2023:4325 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2023:4328 |
| Red Hat Enterprise Linux CRB (v. 9) | Fixed | RHSA-2023:4325 |
| Red Hat Enterprise Linux ResilientStorage (v. 9) | Fixed | RHSA-2023:4325 |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2023-3347
- 2026-10-03 Alias added: GHSA-m82c-5hpw-48f7
References
More Red Hat Enterprise Linux vulnerabilities
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- TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
- TI-2025-23530 Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf… KEVCVSS 3.1CRITICAL 9.3
- TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
Sources
- CVE-2023-3347 · CVE Program
- CVE-2023-3347 · NVD
- FIRST EPSS
- GHSA-m82c-5hpw-48f7 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-3347 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences