COMMAND
WebRamp
SYSTEMS AFFECTED
Systems using WebRamp
PROBLEM
Ramp Networks WebRamp Internet access devices allow multiple
computers to share a dialup connection. The WebRamp family of
Internet access devices are designed for small businesses that
require cost-effective, high-speed Internet access on every
desktop. WebRamp is vulnerable to two denial of service attacks
that allow an attacker to either crash the WebRamp device or
change its IP address. When the device crashes, it will have to
be manually reset before it will dial up. If an attacker changes
the IP address of the WebRamp, none of the machines on your
network will be able to find it, so no machines will be able to
access the Internet via the WebRamp. The device will still
function as a network hub, so your intra-LAN connectivity will not
be disrupted.
WebRamp crash/denial of service attack: Sending a specially
formatted string of characters to the HTTP port of the WebRamp
causes the device to hang, requiring a manual reset.
WebRamp IP address change: Sending a specially-formatted UDP
packet to port 5353 changes the WebRamp's local IP address,
effectively 'hiding' the device from the rest of your machines.
The WebRamp is still connected to the Internet and its PPP IP
address is unchanged.
SOLUTION
If an attacker has crashed your WebRamp, then manually reset it
by turning it off and on again. If an attacker has changed the IP
address, use WRFINDER.EXE on the WebRamp installation CD to change
the address to a proper value. Go to
http://www.rampnet.com/upgrades
to get the latest firmware for your model of WebRamp.