Specifically, he referenced their use by male prostitutes where pregnancy is not possible. Here was the specific statement:
[The Church] of course does not regard [condoms] as a real or moral solution [to the AIDS epidemic], but, in this or that case, there can be nonetheless, in the intention of reducing the risk of infection, a first step in a movement toward a different way, a more human way, of living sexuality.Mollie Hemingway points out that the media has interpreted the statements to mean that the Pope has endorsed the use of condoms on a more widespread basis. That's not the case.
...you may want to read the actual remarks from Benedict, helpfully published by BBC. It’s not long and has plenty of discussion about how the media perverts news. And you might also note that you won’t find the words “permissible,” “justified” or “acceptable” in those remarks. You’ll note that there is literally nothing in there about procreative sex or birth control.