This looks like the bug described here: http://trac.wordpress.org/ticket/3722 "DB error when sanitized search string results in empty query" (Filed January 31) According to that page: > I guess it's also worth mentioning that commas > _are_ being sanitized. The reason for the error is > that once the commas are gone WordPress attempts > to wrap the search query with "AND ( $search )" > > Since $search is null MySQL throws up an error. The same error results from searching for just a space. In either case, adding other characters to the field results in the expected query. It doesn't look like injection would be possible.
