BlackNurse Attack: A Simple Way To Down Large Servers With just a Single Laptop


The researchers from TDC protection Operations center have observed an assault named BlackNurse. It allows an attacker with modest assets to target big firewalls and servers. The BlackNurse assault is based on low-volume ICMP-primarily based site visitors.

Back inside the Nineteen Nineties, human beings have been able to weigh down any other individual’s dial-up internet connection by surely the usage of some ping instructions. A similar kind of denial of provider attack is returned to cripple contemporary day firewalls and take down big servers. Named BlackNurse, this attack mechanism is based on a low-quantity (ICMP)-primarily based attack on vulnerable firewalls, targeting the ones made by way of Cisco, Zyxel, SonicWall and others. For folks who don’t recognize, ICMP is the protocol utilized by the routers and community devices to send/acquire error messages.
Researchers from Denmark’s TDC security Operations middle have these days found this simple attack that makes use of restricted resources. They discovered that even the attacks with low site visitors velocity and packets in keeping with 2nd, usually referred to as a ‘ping flood attack’, have been able to quit the operations of their customers.

The BlackNurse assault uses kind 3 ICMP packets with a code of three. After achieving a threshold of 15-18 Mbps, the goal firewalls drop large packets and the server in the back of the tool will become unable to speak to the internet.

Within the checks, the researchers determined out that simplest a single modest pc was enough to supply a hundred and eighty Mbps BlackNurse volumes. “It does not be counted if you have a 1 Gbit/s net connection. The effect we see on exclusive firewalls is normally excessive CPU masses,” the researchers state.

Greater info on unique fashions of affected gadgets can be determined here.

Palo Alto Networks has issued its advisory and referred to as its devices susceptible simplest in very particular eventualities that contravene pleasant practices. on the other hand, Cisco has refused to consider it a safety risk.


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