Description
The winbind_name_list_to_sid_string_list function in nsswitch/pam_winbind.c in Samba through 4.1.2 handles invalid require_membership_of group names by accepting authentication by any user, which allows remote authenticated users to bypass intended access restrictions in opportunistic circumstances by leveraging an administrator's pam_winbind configuration-file mistake.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | samba | 2:4.0.13+dfsg-1 | — |
| Debian 13 | samba | 2:4.0.13+dfsg-1 | — |
| Debian 12 | samba | 2:4.0.13+dfsg-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | samba | 2:4.0.13+dfsg-1ubuntu1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | samba +11 | 3.6.9-168.el6_5 | RHSA-2014:0330 |
| RHEL 6 | samba4 +13 | 4.0.0-61.el6_5.rc4 | RHSA-2014:0383 |
| RHEL 5 | samba3x +7 | 3.6.6-0.139.el5_10 | RHSA-2014:0330 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | samba | 4.5.0-1.1 | openSUSE-SU-2024:10069-1 |
Advisories 3
- RHSA-2014:0383 Red Hat Security Advisory: samba4 security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2014:0330 Red Hat Security Advisory: samba and samba3x security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- openSUSE-SU-2024:10069-1 ctdb-4.5.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- HPSBUX03087 vendor-advisory
- USN-2054-1 vendor-advisory
- [samba-technical] 20120612 winbind pam security problem mailing-list
- FEDORA-2014-9132 vendor-advisory
- SUSE-SU-2014:0024 vendor-advisory
- openSUSE-SU-2014:0405 vendor-advisory
- GLSA-201502-15 vendor-advisory
- FEDORA-2014-7672 vendor-advisory
- openSUSE-SU-2013:1921 vendor-advisory
- openSUSE-SU-2016:1106 vendor-advisory
- openSUSE-SU-2016:1107 vendor-advisory
- [samba-technical] 20131128 fail authentication if user isn't member of *any* require_membership_of specified groups mailing-list
- [oss-security] 20131202 Re: CVE request: samba pam_winbind authentication fails open mailing-list
- RHSA-2014:0330 vendor-advisory
- https://bugzilla.samba.org/show_bug.cgi?id=10300
- MDVSA-2013:299 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1036897