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Fencer Intel
medium 5.4

CVE-2015-5296 json

Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 supports connections that are encrypted but unsigned, which all…

published 2015-12-29 10 y ago modified 2026-06-17 4 mo ago also EUVD-2015-5273

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
7.3%
EPSS 7.3% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 supports connections that are encrypted but unsigned, which allows man-in-the-middle attackers to conduct encrypted-to-unencrypted downgrade attacks by modifying the client-server data stream, related to clidfs.c, libsmb_server.c, and smbXcli_base.c.

Patch / fix

  • samba samba 4.1.22, 4.2.7, 4.3.3
  • samba Debian 14, Debian 13, Debian 12 2:4.1.22+dfsg-1

debian advisories DEBIAN-CVE-2015-5296

  • samba Ubuntu 14.04 LTS 2:4.1.6+dfsg-1ubuntu2.14.04.11
  • samba Ubuntu 16.04 LTS 2:4.3.3+dfsg-1ubuntu1

ubuntu advisories UBUNTU-CVE-2015-5296

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • samba RHEL 7 4.2.3-11.el7_2
  • ctdb RHEL 7 4.2.3-11.el7_2
  • samba-dc RHEL 7 4.2.3-11.el7_2
  • ctdb-tests RHEL 7 4.2.3-11.el7_2
  • samba-libs RHEL 7 4.2.3-11.el7_2
  • samba-pidl RHEL 7 4.2.3-11.el7_2
  • samba-test RHEL 7 4.2.3-11.el7_2
  • libwbclient RHEL 7 4.2.3-11.el7_2

red hat advisories RHSA-2016:0006RHSA-2016:0016RHSA-2016:0015RHSA-2016:0010RHSA-2016:0011

  • samba SLES for SAP 11 SP4, SLES for SAP 11 SP3, SLES 11 SP4 +6 more 3.6.3-64.1
  • tevent SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 +1 more 0.9.26-4.1
  • ldb SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 +1 more 1.1.24-4.1
  • tdb SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 +1 more 1.3.8-4.1
  • samba SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 +1 more 4.2.4-6.1
  • talloc SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 +1 more 2.1.5-4.1
  • tevent SLES for SAP 12, SLES 12, SLED 12 +1 more 0.9.26-3.3.1
  • ldb SLES for SAP 12, SLES 12, SLED 12 +1 more 1.1.24-4.3.1

suse advisories SUSE-SU-2016:0164-1SUSE-SU-2016:0032-1SUSE-SU-2015:2305-1SUSE-SU-2015:2304-1

  • samba openSUSE Tumbleweed 4.5.0-1.1

opensuse advisories openSUSE-SU-2024:10069-1

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-2015-5296 updated cvss 5.8

samba: client requesting encryption vulnerable to downgrade attack

  • Red Hat Enterprise Linux 5 samba3x
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux Client (v. 7) samba 4.2.3-11.el7_2, samba-libs 4.2.3-11.el7_2, libwbclient 4.2.3-11.el7_2, libsmbclient 4.2.3-11.el7_2, samba-client 4.2.3-11.el7_2, samba-common 4.2.3-11.el7_2, +6 more Red Hat Enterprise Linux Client Optional (v. 7) samba 4.2.3-11.el7_2, samba-dc 4.2.3-11.el7_2, samba-pidl 4.2.3-11.el7_2, samba-test 4.2.3-11.el7_2, samba-python 4.2.3-11.el7_2, samba-dc-libs 4.2.3-11.el7_2, +3 more Red Hat Enterprise Linux ComputeNode (v. 7) samba 4.2.3-11.el7_2, samba-libs 4.2.3-11.el7_2, libwbclient 4.2.3-11.el7_2, libsmbclient 4.2.3-11.el7_2, samba-client 4.2.3-11.el7_2, samba-common 4.2.3-11.el7_2, +6 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) samba 4.2.3-11.el7_2, samba-dc 4.2.3-11.el7_2, samba-pidl 4.2.3-11.el7_2, samba-test 4.2.3-11.el7_2, samba-python 4.2.3-11.el7_2, samba-dc-libs 4.2.3-11.el7_2, +3 more
    fixed: vendor fix RHSA-2016:0006
  • Red Hat Enterprise Linux Desktop (v. 6) samba 3.6.23-24.el6_7, samba4 4.0.0-67.el6_7.rc4, libsmbclient 3.6.23-24.el6_7, samba-client 3.6.23-24.el6_7, samba-common 3.6.23-24.el6_7, samba4-dc 4.0.0-67.el6_7.rc4, +13 more Red Hat Enterprise Linux Desktop Optional (v. 6) samba 3.6.23-24.el6_7, samba-swat 3.6.23-24.el6_7, samba-glusterfs 3.6.23-24.el6_7, samba-domainjoin-gui 3.6.23-24.el6_7, samba-winbind-krb5-locator 3.6.23-24.el6_7 Red Hat Enterprise Linux HPC Node (v. 6) samba 3.6.23-24.el6_7, samba4 4.0.0-67.el6_7.rc4, samba-client 3.6.23-24.el6_7, samba-common 3.6.23-24.el6_7, samba4-dc 4.0.0-67.el6_7.rc4, samba-winbind 3.6.23-24.el6_7, +12 more Red Hat Enterprise Linux HPC Node Optional (v. 6) samba 3.6.23-24.el6_7, samba-swat 3.6.23-24.el6_7, libsmbclient 3.6.23-24.el6_7, samba-glusterfs 3.6.23-24.el6_7, samba-domainjoin-gui 3.6.23-24.el6_7, samba-winbind-krb5-locator 3.6.23-24.el6_7 Red Hat Enterprise Linux Server (v. 6) samba 3.6.23-24.el6_7, samba4 4.0.0-67.el6_7.rc4, libsmbclient 3.6.23-24.el6_7, samba-client 3.6.23-24.el6_7, samba-common 3.6.23-24.el6_7, samba4-dc 4.0.0-67.el6_7.rc4, +13 more
    fixed: vendor fix RHSA-2016:0011
  • Red Hat Enterprise Linux Server (v. 7) samba 4.2.3-11.el7_2, samba-libs 4.2.3-11.el7_2, libwbclient 4.2.3-11.el7_2, libsmbclient 4.2.3-11.el7_2, samba-client 4.2.3-11.el7_2, samba-common 4.2.3-11.el7_2, +7 more
    fixed: vendor fix RHSA-2016:0006
  • Red Hat Enterprise Linux Server Optional (v. 6) samba-swat 3.6.23-24.el6_7, samba-glusterfs 3.6.23-24.el6_7, samba-domainjoin-gui 3.6.23-24.el6_7, samba-winbind-krb5-locator 3.6.23-24.el6_7
    fixed: vendor fix RHSA-2016:0011
  • Red Hat Enterprise Linux Server Optional (v. 7) samba-dc 4.2.3-11.el7_2, samba-pidl 4.2.3-11.el7_2, samba-test 4.2.3-11.el7_2, samba-python 4.2.3-11.el7_2, samba-dc-libs 4.2.3-11.el7_2, samba-test-libs 4.2.3-11.el7_2, +2 more Red Hat Enterprise Linux Server Resilient Storage (v. 7) ctdb 4.2.3-11.el7_2, ctdb-tests 4.2.3-11.el7_2
    fixed: vendor fix RHSA-2016:0006
  • Red Hat Enterprise Linux Workstation (v. 6) samba 3.6.23-24.el6_7, samba4 4.0.0-67.el6_7.rc4, libsmbclient 3.6.23-24.el6_7, samba-client 3.6.23-24.el6_7, samba-common 3.6.23-24.el6_7, samba4-dc 4.0.0-67.el6_7.rc4, +13 more
    fixed: vendor fix RHSA-2016:0011
  • Red Hat Enterprise Linux Workstation (v. 7) samba 4.2.3-11.el7_2, samba-libs 4.2.3-11.el7_2, libwbclient 4.2.3-11.el7_2, libsmbclient 4.2.3-11.el7_2, samba-client 4.2.3-11.el7_2, samba-common 4.2.3-11.el7_2, +7 more
    fixed: vendor fix RHSA-2016:0006
show 5 more
  • Red Hat Enterprise Linux Workstation Optional (v. 6) samba-swat 3.6.23-24.el6_7, samba-glusterfs 3.6.23-24.el6_7, samba-domainjoin-gui 3.6.23-24.el6_7, samba-winbind-krb5-locator 3.6.23-24.el6_7
    fixed: vendor fix RHSA-2016:0011
  • Red Hat Enterprise Linux Workstation Optional (v. 7) samba-dc 4.2.3-11.el7_2, samba-pidl 4.2.3-11.el7_2, samba-test 4.2.3-11.el7_2, samba-dc-libs 4.2.3-11.el7_2, samba-test-libs 4.2.3-11.el7_2, samba-vfs-glusterfs 4.2.3-11.el7_2, +1 more
    fixed: vendor fix RHSA-2016:0006
  • Red Hat Gluster 3 Samba on RHEL-6 samba 4.1.17-16.el6rhs, samba-dc 4.1.17-16.el6rhs, samba-libs 4.1.17-16.el6rhs, samba-pidl 4.1.17-16.el6rhs, samba-test 4.1.17-16.el6rhs, libwbclient 4.1.17-16.el6rhs, +11 more
    fixed: vendor fix RHSA-2016:0015
  • Red Hat Gluster 3 Samba on RHEL-7 ctdb 4.2.4-9.1.el7rhgs, samba 4.2.4-9.1.el7rhgs, samba-dc 4.2.4-9.1.el7rhgs, ctdb-tests 4.2.4-9.1.el7rhgs, samba-libs 4.2.4-9.1.el7rhgs, samba-pidl 4.2.4-9.1.el7rhgs, +16 more
    fixed: vendor fix RHSA-2016:0016
  • Red Hat Enterprise Linux 5 samba
    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

7.26% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel 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.