CVE-2019-18277

A flaw was found in HAProxy before 2.0.6. In legacy mode, messages
featuring a transfer-encoding header missing the “chunked” value were not
being correctly rejected. The impact was limited but if combined with the
“http-reuse always” setting, it could be used to help construct an HTTP
request smuggling attack against a vulnerable component employing a lenient
parser that would ignore the content-length header as soon as it saw a
transfer-encoding one (even if not entirely valid according to the
specification).