GHSA-8VM2-C32J-MVFR Apache NiFi fails to validate proxy host headers when constructing qualified URLs

Apache NiFi 0.0.1 through 2.9.0 support building qualified URLs from one of several HTTP request headers that provide an alternative to the standard Host header without validating the values provided. Apache NiFi 1.6.0 introduced a configurable application property to restrict values provided in...