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Fencer Vulns
critical 9.1

CVE-2023-3961 json

Samba: smbd allows client access to unix domain sockets on the file system as root

published 2023-11-03 3 y ago modified 2026-11-07 2 d ago also EUVD-2023-44586

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.7%
EPSS 2.7% chance of exploitation in 30 days, percentile 85%
public exploits
0
none known

Summary

A path traversal vulnerability was identified in Samba when processing client pipe names connecting to Unix domain sockets within a private directory. Samba typically uses this mechanism to connect SMB clients to remote procedure call (RPC) services like SAMR LSA or SPOOLSS, which Samba initiates on demand. However, due to inadequate sanitization of incoming client pipe names, allowing a client to send a pipe name containing Unix directory traversal characters (../). This could result in SMB clients connecting as root to Unix domain sockets outside the private directory. If an attacker or client managed to send a pipe name resolving to an external service using an existing Unix domain socket, it could potentially lead to unauthorized access to the service and consequential adverse events, including compromise or service crashes.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 8 0:4.18.6-2.el8_9
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support 0:4.15.5-13.el8_6
  • Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support 0:4.17.5-4.el8_8
  • Red Hat Red Hat Enterprise Linux 9 0:4.18.6-101.el9_3
  • Red Hat Red Hat Enterprise Linux 9.0 Extended Update Support 0:4.15.5-111.el9_0
  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support 0:4.17.5-104.el9_2
  • Red Hat Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 0:4.15.5-13.el8_6
  • samba Debian 12 2:4.17.12+dfsg-0+deb12u1
  • samba Debian 14, Debian 13 2:4.19.1+dfsg-1

debian advisories DEBIAN-CVE-2023-3961

  • samba RHEL 8 4.18.6-2.el8_9
  • ctdb RHEL 8 4.18.6-2.el8_9
  • libnetapi RHEL 8 4.18.6-2.el8_9
  • samba-libs RHEL 8 4.18.6-2.el8_9
  • samba-pidl RHEL 8 4.18.6-2.el8_9
  • samba-test RHEL 8 4.18.6-2.el8_9
  • libwbclient RHEL 8 4.18.6-2.el8_9
  • samba-tools RHEL 8 4.18.6-2.el8_9

red hat advisories RHSA-2023:7467RHSA-2023:7464RHSA-2023:7408RHSA-2023:7371RHSA-2023:6744RHSA-2023:6209

  • samba SLE Module for Basesystem 15 SP5, SLE Micro 5.5, SLE High Availability Extension 15 SP5 +1 more 4.17.9+git.421.abde31ca5c2-150500.3.11.1

suse advisories SUSE-SU-2023:4046-1

  • samba openSUSE Tumbleweed 4.19.1+git.312.c912b3d2ef6-1.1

opensuse advisories openSUSE-SU-2024:13332-1

  • samba AlmaLinux 8 4.18.6-2.el8_9.alma.1
  • ctdb AlmaLinux 8 4.18.6-2.el8_9.alma.1
  • libnetapi AlmaLinux 8 4.18.6-2.el8_9.alma.1
  • samba-libs AlmaLinux 8 4.18.6-2.el8_9.alma.1
  • samba-pidl AlmaLinux 8 4.18.6-2.el8_9.alma.1
  • samba-test AlmaLinux 8 4.18.6-2.el8_9.alma.1
  • libwbclient AlmaLinux 8 4.18.6-2.el8_9.alma.1
  • samba-tools AlmaLinux 8 4.18.6-2.el8_9.alma.1

almalinux advisories ALSA-2023:7467ALSA-2023:6744

  • samba Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 4.18.8-r0

alpine advisories ALPINE-CVE-2023-3961

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-3961 updated cvss 9.1

samba: smbd allows client access to unix domain sockets on the file system as root

  • Red Hat Storage 3 ctdb, samba, samba-dc, ctdb-tests, samba-libs, samba-pidl, +21 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) samba-devel 4.18.6-2.el8_9, ctdb-debuginfo 4.18.6-2.el8_9, libnetapi-devel 4.18.6-2.el8_9, samba-debuginfo 4.18.6-2.el8_9, libwbclient-devel 4.18.6-2.el8_9, samba-debugsource 4.18.6-2.el8_9, +24 more
    fixed: vendor fix RHSA-2023:7467
  • Red Hat CodeReady Linux Builder (v. 9) samba-pidl 4.18.6-101.el9_3, samba-test 4.18.6-101.el9_3, samba-test-libs 4.18.6-101.el9_3, python3-samba-test 4.18.6-101.el9_3
    fixed: vendor fix RHSA-2023:6744
  • Red Hat CodeReady Linux Builder EUS (v.8.6) samba-devel 4.15.5-13.el8_6, ctdb-debuginfo 4.15.5-13.el8_6, samba-debuginfo 4.15.5-13.el8_6, libwbclient-devel 4.15.5-13.el8_6, samba-debugsource 4.15.5-13.el8_6, libsmbclient-devel 4.15.5-13.el8_6, +17 more
    fixed: vendor fix RHSA-2023:7408
  • Red Hat CodeReady Linux Builder EUS (v.8.8) samba-devel 4.17.5-4.el8_8, ctdb-debuginfo 4.17.5-4.el8_8, libnetapi-devel 4.17.5-4.el8_8, samba-debuginfo 4.17.5-4.el8_8, libwbclient-devel 4.17.5-4.el8_8, samba-debugsource 4.17.5-4.el8_8, +24 more
    fixed: vendor fix RHSA-2023:7464
  • Red Hat CodeReady Linux Builder EUS (v.9.0) samba-pidl 4.15.5-111.el9_0, samba-test 4.15.5-111.el9_0, samba-test-libs 4.15.5-111.el9_0
    fixed: vendor fix RHSA-2023:6209
  • Red Hat CodeReady Linux Builder EUS (v.9.2) samba-pidl 4.17.5-104.el9_2, samba-test 4.17.5-104.el9_2, samba-test-libs 4.17.5-104.el9_2, python3-samba-test 4.17.5-104.el9_2
    fixed: vendor fix RHSA-2023:7371
  • Red Hat Enterprise Linux AppStream (v. 8) samba-vfs-iouring 4.18.6-2.el8_9
    fixed: vendor fix RHSA-2023:7467
show 16 more
  • Red Hat Enterprise Linux AppStream (v. 9) samba-client 4.18.6-101.el9_3, samba-winexe 4.18.6-101.el9_3, samba-vfs-iouring 4.18.6-101.el9_3, samba-krb5-printing 4.18.6-101.el9_3, samba-winbind-clients 4.18.6-101.el9_3, samba-winbind-krb5-locator 4.18.6-101.el9_3
    fixed: vendor fix RHSA-2023:6744
  • Red Hat Enterprise Linux AppStream EUS (v.8.6) samba-vfs-iouring 4.15.5-13.el8_6
    fixed: vendor fix RHSA-2023:7408
  • Red Hat Enterprise Linux AppStream EUS (v.8.8) samba-vfs-iouring 4.17.5-4.el8_8
    fixed: vendor fix RHSA-2023:7464
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) samba-client 4.15.5-111.el9_0, samba-winexe 4.15.5-111.el9_0, samba-vfs-iouring 4.15.5-111.el9_0, samba-krb5-printing 4.15.5-111.el9_0, samba-winbind-clients 4.15.5-111.el9_0, samba-winbind-krb5-locator 4.15.5-111.el9_0
    fixed: vendor fix RHSA-2023:6209
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) samba-client 4.17.5-104.el9_2, samba-winexe 4.17.5-104.el9_2, samba-vfs-iouring 4.17.5-104.el9_2, samba-krb5-printing 4.17.5-104.el9_2, samba-winbind-clients 4.17.5-104.el9_2, samba-winbind-krb5-locator 4.17.5-104.el9_2
    fixed: vendor fix RHSA-2023:7371
  • Red Hat Enterprise Linux BaseOS (v. 8) ctdb 4.18.6-2.el8_9, samba 4.18.6-2.el8_9, libnetapi 4.18.6-2.el8_9, samba-libs 4.18.6-2.el8_9, samba-pidl 4.18.6-2.el8_9, samba-test 4.18.6-2.el8_9, +22 more
    fixed: vendor fix RHSA-2023:7467
  • Red Hat Enterprise Linux BaseOS (v. 9) samba 4.18.6-101.el9_3, libnetapi 4.18.6-101.el9_3, samba-libs 4.18.6-101.el9_3, libwbclient 4.18.6-101.el9_3, samba-tools 4.18.6-101.el9_3, libsmbclient 4.18.6-101.el9_3, +12 more
    fixed: vendor fix RHSA-2023:6744
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) ctdb 4.15.5-13.el8_6, samba 4.15.5-13.el8_6, samba-libs 4.15.5-13.el8_6, samba-pidl 4.15.5-13.el8_6, samba-test 4.15.5-13.el8_6, libwbclient 4.15.5-13.el8_6, +15 more
    fixed: vendor fix RHSA-2023:7408
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) ctdb 4.17.5-4.el8_8, samba 4.17.5-4.el8_8, libnetapi 4.17.5-4.el8_8, samba-libs 4.17.5-4.el8_8, samba-pidl 4.17.5-4.el8_8, samba-test 4.17.5-4.el8_8, +22 more
    fixed: vendor fix RHSA-2023:7464
  • Red Hat Enterprise Linux BaseOS EUS (v.9.0) samba 4.15.5-111.el9_0, samba-libs 4.15.5-111.el9_0, libwbclient 4.15.5-111.el9_0, libsmbclient 4.15.5-111.el9_0, samba-common 4.15.5-111.el9_0, python3-samba 4.15.5-111.el9_0, +5 more
    fixed: vendor fix RHSA-2023:6209
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) samba 4.17.5-104.el9_2, libnetapi 4.17.5-104.el9_2, samba-libs 4.17.5-104.el9_2, libwbclient 4.17.5-104.el9_2, samba-tools 4.17.5-104.el9_2, libsmbclient 4.17.5-104.el9_2, +12 more
    fixed: vendor fix RHSA-2023:7371
  • Red Hat Enterprise Linux Resilient Storage (v. 9) ctdb 4.18.6-101.el9_3
    fixed: vendor fix RHSA-2023:6744
  • Red Hat Enterprise Linux Resilient Storage EUS (v.9.0) ctdb 4.15.5-111.el9_0
    fixed: vendor fix RHSA-2023:6209
  • Red Hat Enterprise Linux Resilient Storage EUS (v.9.2) ctdb 4.17.5-104.el9_2
    fixed: vendor fix RHSA-2023:7371
  • Red Hat Virtualization 4 Hypervisor for RHEL 8 samba 4.15.5-13.el8_6, libwbclient 4.15.5-13.el8_6, libsmbclient 4.15.5-13.el8_6, samba-common 4.15.5-13.el8_6, samba-client-libs 4.15.5-13.el8_6, samba-common-libs 4.15.5-13.el8_6
    fixed: vendor fix RHSA-2023:7408
  • Red Hat Enterprise Linux 6 samba, samba4, samba4-dc, samba-swat, samba4-libs, samba4-pidl, +17 more Red Hat Enterprise Linux 7 ctdb, samba, samba-dc, ctdb-tests, samba-libs, samba-pidl, +18 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.69% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.samba.org https://bugzilla.samba.org/show_bug.cgi?id=15422 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support
  • Red Hat Red Hat Virtualization 4 for Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Storage 3

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.