NIST SP800-38F specifies key wrapping algorithms. An important distinction between KW (without padding) and KWP (with padding) seems to be that KW cannot be used to wrap keys of length 8 bytes i.e. 1 semiblock in the NIST specification. On the other hand, KWP is allowed to wrap keys of size less than 16 bytes. Is there a catastrophic failure if a (broken) KW implementation supports wrapping 8 byte keys?