CVE-2019-15134

RIOT through 2019.07 contains a memory leak in the TCP implementation (gnrc_tcp), allowing an attacker to consume all memory available for network packets and thus effectively stopping all network threads from working. This is related to _receive in sys/net/gnrc/transport_layer/tcp/gnrc_tcp_eventloop.c upon receiving an ACK before a SYN.

Source: CVE-2019-15134