A new wave of malicious attack has been discovered.  This one doesn't attack your programs or your data.  It doesn't take advantage of some software flaw or bombard the network stack.  This attack is more damaging.  This attack is permanent.  The Permanent Denial of Service attack is a relatively new method for attackers to cause harm to an organization.

Primarily targeting the update function in firmware, well planned PDoS attacks can decimate a company's network infrastructure, bricking every switch, router, and firewall in the building.  While this attack is brand new and hasn't even been found in the wild, it presents a devastating risk to a fairly benign part of IT systems.  Embedded device firmware is usually something IT managers don't have to worry about often and its quite possible that if PDoS attacks, aka "phlashing", become prevalent, millions of dollars in equipment could be lost.

The method of doing this was discovered by HP Systems Security Labs.  RIch Smith of HPSSL demonstrated his phlashing tool, PhlashDance, at the EUSecWest conference in London.  Its basically a fuzzer that attacks the firmware's binaries and update protocol.

About the only thing you can do to protect yourself at this time is to implement authentication on your devices.  You can read more about phlashing at DarkReading.