There's actually a message that shows up on recently bumped questions:
bumped to the homepage by Community♦ 13 mins ago
This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Community is trying to draw attention to questions that have answers scored zero, but no answers scored above zero, because SE wants users to review these answers and either upvote or downvote them. That's why the message is written the way it is.
It picks open questions which have a score of at least zero, and it's biased in favor of questions that have more views. The details can be found here, on the network-wide meta: What can cause a question to be bumped?
When you see a question that's been bumped by Community, if you'd like to help, you can review the answers and either upvote or downvote, or you can take any other action you feel is appropriate. If the question isn't attracting answers because the question itself is unclear, for example, you could vote to close or try to work with the OP to get some more details to bring the question into an answerable state. Or you could edit the question yourself, if you think you can make whatever changes it needs.
Just use your judgment and do whatever you'd do for any other question, in other words.