A flaw was reported in WildFly 12.0.0.CR1 web server is vulnerable to the injection of arbitrary HTTP Header due to insufficient sanitisation and validation of user UTF-8 encoded input before it is used as part of an HTTP header value.

Although there is a protection against CRLF injection by detecting the presence of a NewLine character (0x0a), it can be bypassed using characters encoded in UTF-8 as the page will try to convert them back to the original Unicode form and extract the last byte.