Efficient Networks 5861 DSL router, when running firmware 5.3.80 configured to block incoming TCP SYN, packets allows remote attackers to cause a denial of service (crash) via a flood of TCP SYN packets to the WAN interface using a port scanner such as nmap.

Efficient Networks 5861 DSL router, when running firmware 5.3.80 configured to block incoming TCP SYN, packets allows remote attackers to cause a denial of service (crash) via a flood of TCP SYN packets to the WAN interface using a port scanner such as nmap.

Efficient Networks 5861 DSL router, when running firmware 5.3.80 configured to block incoming TCP SYN, packets allows remote attackers to cause a denial of service (crash) via a flood of TCP SYN packets to the WAN interface using a port scanner such as nmap. A denial of service vulnerability has been reported for the Efficient Networks 5861 line of DSL routers. The vulnerability can be triggered when the router is configured to block incoming TCP SYN flags and is subsequently portscanned. An attacker can exploit this vulnerability by portscanning a vulnerable DSL router on its WAN interface. When this occurs the device will reportedly lock up and then restart after a period of time. The Efficient Networks DSL Router is a small ADSL router that offers features like firewall and VPN