== Workarounds == === Rewoking change passwords rights === Rewoke the change passwords right for everyone from all user objects (including computers) in the directory. Note that this will prevent users from being able to change their own expired passwords, so the maximum password age should be set to a value that prevents user passwords from expiring while the workaround is in place. The change password right in AD is an extended object access right with the GUID ab721a53-1e2f-11d0-9819-00aa0040529b. By default every user and computer object in the directory grants the change password right to self and everyone. The corresponding ACEs are
self: (OA;;CR;ab721a53-1e2f-11d0-9819-00aa0040529b;;PS) world: (OA;;CR;ab721a53-1e2f-11d0-9819-00aa0040529b;;WD)in SDDL. The components of these ACEs are OA: object access allowed CR: extended rights PS,WD: trustee: self, everyone Of these, the ACE granting the right to everyone (world, WD) must be removed. The ACL of any object in the Samba directory can be shown as SDDL with
# ldbsearch -H /var/lib/samba/private/sam.ldb cn=USER ntSecurityDescriptorNote that the path to '''sam.ldb''' depends on the Samba build configuration. Alternatively, the ACL can be shown in NDR dump format by appending '''--show-binary''':
# ldbsearch -H /var/lib/samba/private/sam.ldb \ cn=USER ntSecurityDescriptor --show-binary ... aces: struct security_ace type : SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT (5) flags : 0x00 (0) 0: SEC_ACE_FLAG_OBJECT_INHERIT 0: SEC_ACE_FLAG_CONTAINER_INHERIT 0: SEC_ACE_FLAG_NO_PROPAGATE_INHERIT 0: SEC_ACE_FLAG_INHERIT_ONLY 0: SEC_ACE_FLAG_INHERITED_ACE 0x00: SEC_ACE_FLAG_VALID_INHERIT (0) 0: SEC_ACE_FLAG_SUCCESSFUL_ACCESS 0: SEC_ACE_FLAG_FAILED_ACCESS size : 0x0028 (40) access_mask : 0x00000100 (256) object : union security_ace_object_ctr(case 5) object: struct security_ace_object flags : 0x00000001 (1) 1: SEC_ACE_OBJECT_TYPE_PRESENT 0: SEC_ACE_INHERITED_OBJECT_TYPE_PRESENT type : union security_ace_object_type(case 1) type : ab721a53-1e2f-11d0-9819-00aa0040529b inherited_type : union security_ace_object_inherited_type(case 0) trustee : S-1-1-0 ...To temporarily remove this ACE you can use ldbedit:
# ldbedit -H /var/lib/samba/private/sam.ldb cn=USER ntSecurityDescriptorThis invokes the configured editor. In the editor search for the string
(OA;;CR;ab721a53-1e2f-11d0-9819-00aa0040529b;;WD)and remove it (be careful about line wraps). Saving and exiting the editor will apply the change to the directory.