I have seen a few answers here and elsewhere that say a salt doesn't need to be cryptographically secure randomness but rather just unique since they are stored in the open anyway. I am working on an implementation of PBKDF2 and AES-CBC and reading NIST SP 800-132 Recommendation for Password-Based Key Derivation from 2010, it states in section 5 regarding salts:
All or a portion of the salt shall be generated using an approved Random Bit Generator (e.g., see ). The length of the randomly-generated portion of the salt shall be at least 128 bits.
I don't personally care whether it needs excellent randomness or not but I just want to get it cleared up for my own sake whether the NIST recommendation contradicts that salts don't need to be cryptographically secure.