Samba versions 3.4.x to 3.6.4 inclusive are affected
by a vulnerability that allows arbitrary users to modify
privileges on a file server.
Security checks were incorrectly applied to the Local
Security Authority (LSA) remote proceedure calls (RPC)
CreateAccount, OpenAccount, AddAccountRights and
RemoveAccountRights allowing any authenticated user
to modify the privileges database.
This is a serious error, as it means that authenticated
users can connect to the LSA and grant themselves the
"take ownership" privilege. This privilege is used by the
smbd file server to grant the ability to change ownership
of a file or directory which means users could take ownership
of files or directories they do not own.