What parts of AES encryption result are safe to pass on the network I'm using AES to encrypt the message.
both sender and receiver know the passphrase, but only sender knows IV and salt

I assume that receiver also needs to know IV and salt to decypher text;

is it safe to pass IV and salt along with the cyphertext over an unsecured network, or will this compromise the security?

I'm using https://code.google.com/p/crypto-js to send encrypted messages between multiple clients.
IVs and salts are public, so they are safe to pass with the ciphertext. They should be authenticated along with the ciphertext though.