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6 <title>Samba - Security Announcement Archive</title>
11 <H2>CVE-2018-1057.html:</H2>
15 ====================================================================
16 == Subject: Authenticated users can change other users' password
18 == CVE ID#: CVE-2018-1057
20 == Versions: All versions of Samba from 4.0.0 onwards.
22 == Summary: On a Samba 4 AD DC any authenticated user can change
23 == other users' passwords over LDAP, including the
24 == passwords of administrative users and service
27 ====================================================================
33 On a Samba 4 AD DC the LDAP server in all versions of Samba from
34 4.0.0 onwards incorrectly validates permissions to modify passwords
35 over LDAP allowing authenticated users to change any other users'
36 passwords, including administrative users and privileged service
37 accounts (eg Domain Controllers).
39 The LDAP server incorrectly validates certain LDAP password
40 modifications against the "Change Password" privilege, but then
41 performs a password reset operation.
43 The change password right in AD is an extended object access right
44 with the GUID ab721a53-1e2f-11d0-9819-00aa0040529b.
46 By default user objects grant the change password right to the
47 authenticated user's own user object (self) and to everyone
48 (world). Computer objects grant the change password right to
51 The corresponding ACEs expressed in SDDL are
53 self: (OA;;CR;ab721a53-1e2f-11d0-9819-00aa0040529b;;PS)
54 world: (OA;;CR;ab721a53-1e2f-11d0-9819-00aa0040529b;;WD)
56 The components of these ACEs are
58 OA: object access allowed
61 WD: trustee: world/everyone
63 The problematic ACE is the one for world/everyone.
65 The Windows GUI shows this as "Change password" right granted to
72 Possible workarounds are described at a dedicated page in the Samba wiki:
74 https://wiki.samba.org/index.php/CVE-2018-1057
80 A patch addressing this defect has been posted to
82 https://www.samba.org/samba/security/
84 Additionally, Samba 4.7.6, 4.6.14 and 4.5.16 have been issued as
85 security releases to correct the defect. Patches against older Samba
86 versions may be available at https://samba.org/samba/patches/. Samba
87 vendors and administrators running affected versions are advised to
88 upgrade or apply the patch as soon as possible.
94 This problem was found by Björn Baumbach from SerNet. Ralph Böhme and
95 Stefan Metzmacher from SerNet and the Samba Team provided the fix.