Beginner question - how to avoid replication of corrupt data in an active/active design?

Hi,

I'm doing some general research and one thing I can't seem to answer is, in a high availability design, if there is "live" replication across two sites, won't a corruption on one component affect the other site, thereby bringing the whole thing down?

Is there anything I am missing?

Apologies if this isn't the right sub for this - would appreciate pointers to an alternative if so.

Thanks