Content-Type header in body

RFC violation is pretty serious and the risks are quite high - just Google for "CRLF Injection" to see the dangers of such attacks.

You should really speak to application developers to get them to fix this and remove the CRLF injection vulnerability. If fixing the application code is not possible then you need to very carefully consider the exception - you might need to do it with an iRule and only allow the exception from Trusted IP address rather than the whole Internet.