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).

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).

Se encontró un fallo en HAProxy versiones anteriores a 2.0.6. En el modo legacy, los mensajes caracterizados por un encabezado de codificación de transferencia que no tenía el valor "chunked" no habían sido rechazados correctamente. El impacto fue limitado, pero si se combina con la configuración "http-reuse always", podría usarse para ayudar a construir un ataque de tráfico no autorizado de peticiones HTTP contra un componente vulnerable que emplee un analizador permisivo que ignore el encabezado de longitud de contenido tan pronto como se visualice uno de codificación de transferencia (incluso si no es completamente válido de acuerdo con la especificación).