CVE-2019-9749

An issue was discovered in the MQTT input plugin in Fluent Bit through 1.0.4. When this plugin acts as an MQTT broker (server), it mishandles incoming network messages. After processing a crafted packet, the plugin's mqtt_packet_drop function (in /plugins/in_mqtt/mqtt_prot.c) executes the memmove() function with a negative size parameter. That leads to a crash of the whole Fluent Bit server via a SIGSEGV signal.

An issue was discovered in the MQTT input plugin in Fluent Bit through 1.0.4. When this plugin acts as an MQTT broker (server), it mishandles incoming network messages. After processing a crafted packet, the plugin's mqtt_packet_drop function (in /plugins/in_mqtt/mqtt_prot.c) executes the memmove() function with a negative size parameter. That leads to a crash of the whole Fluent Bit server via a SIGSEGV signal.

Se ha descubierto un problema en el plugin de entradas MQTT en Fluent Bit hasta la CVErsión 1.0.4. Cuando este plugin actúa como broker MQTT (servidor), gestiona de manera incorrecta los mensajes de red entrantes. Tras procesar un paquete manipulado, la función del plugin mqtt_packet_drop (en /plugins/in_mqtt/mqtt_prot.c) ejecuta la función memmoCVE() con un parámetro de tamaño negativo. Esto conduce a un cierre inesperado de todo el servidor Fluent Bit mediante una señal SIGSEGV.