All I'm seeing is a missing db_like which means a user can search for "%foo%bar%" instead of just "foo%bar". This is not a SQL-injection, nor a relevant issue.
The problem is in that function though. It is missing a condition for publication status. Titles of unpublished nodes should render for some users, but not all.
The problem is in that function though. It is missing a condition for publication status. Titles of unpublished nodes should render for some users, but not all.