Cisco HTTP possible bug:

[Keith Woodworth]

If you have:

ip http server

in your running config (not a great idea to have on a live router IMO) on
your router and you do:

http://<router-ip>/%%

it crashes said router. I confirmed this on my 1005 running 11.1(24) and
another fellow said it worked on his 2621 and 2524. Though he didnt give
IOS versions.

Had to power cycle the 1005 to get it to work again. Couldnt reach it with
telnet, http or via console cable.

Just an observation.