The Iranians had lots of help pulling this off if indeed they did pull it off. A supercavitating weapon is not only difficult to design, it is difficult to manufacture and the likes of the Russians (who have been most advanced in this area) and the Chinese have been trying to develop them with the express interest of sinking US carriers with them.
I wonder how the Iranians got their hands of the technology? Hmmm? [/sarcasm]