CVE-2021-32780

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions Envoy transitions a H/2 connection to the CLOSED state when it receives a GOAWAY frame without any streams outstanding. The connection state is transitioned to DRAINING when it receives a SETTING frame with the SETTINGS_MAX_CONCURRENT_STREAMS parameter set to 0. Receiving these two frames in the same I/O event results in abnormal termination of the Envoy process due to invalid state transition from CLOSED to DRAINING. A sequence of H/2 frames delivered by an untrusted upstream server will result in Denial of Service in the presence of untrusted **upstream** servers. Envoy versions 1.19.1, 1.18.4 contain fixes to stop processing of pending H/2 frames after connection transition to the CLOSED state.

Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions Envoy transitions a H/2 connection to the CLOSED state when it receives a GOAWAY frame without any streams outstanding. The connection state is transitioned to DRAINING when it receives a SETTING frame with the SETTINGS_MAX_CONCURRENT_STREAMS parameter set to 0. Receiving these two frames in the same I/O event results in abnormal termination of the Envoy process due to invalid state transition from CLOSED to DRAINING. A sequence of H/2 frames delivered by an untrusted upstream server will result in Denial of Service in the presence of untrusted **upstream** servers. Envoy versions 1.19.1, 1.18.4 contain fixes to stop processing of pending H/2 frames after connection transition to the CLOSED state.

Envoy es un proxy L7 de código abierto y un bus de comunicación diseñado para grandes arquitecturas modernas orientadas a servicios. En las versiones afectadas, Envoy lleva a cabo una transición de una conexión H/2 al estado CLOSED cuando recibe una trama GOAWAY sin ningún flujo pendiente. El estado de la conexión pasa a DRAINING cuando recibe una trama SETTING con el parámetro SETTINGS_MAX_CONCURRENT_STREAMS ajustado a 0. Recibiendo estas dos tramas en el mismo evento de E/S resulta en una terminación anormal del proceso Envoy debido a una transición de estado no válida de CLOSED a DRAINING. Una secuencia de tramas H/2 entregada por un servidor upstream no confiable resultará en una Denegación de Servicio en presencia de servidores **upstream** no confiables. Envoy versiones 1.19.1 y 1.18.4, contienen correcciones para detener el procesamiento de las tramas H/2 pendientes después de la transición de la conexión al estado CLOSED.