A denial of service flaw was found in the way the server component of Freeciv before 2.3.4 processed certain packets. A remote attacker could send a specially-crafted packet that, when processed would lead to memory exhaustion or excessive CPU consumption.
packets.c in Freeciv 2.0 before 2.0.8 allows remote attackers to cause a denial of service (server crash) via crafted packets with negative compressed size values.