An issue was discovered in Embedthis GoAhead before 4.0.1 and Appweb before 7.0.2. An HTTP POST request with a specially crafted "Host" header field may cause a NULL pointer dereference and thus cause a denial of service, as demonstrated by the lack of a trailing ']' character in an IPv6 address.
https://github.com/embedthis/goahead/issues/264
https://github.com/embedthis/appweb/issues/605
https://github.com/embedthis/appweb/commit/16e6979c82297d5fc4f8661e7ada975f51e4dfa9