Take a look at the following attack on a Web Server using obstructed URL:
http://www.example.com/script.ext?template=%2e%2e%2f%2e%2e%2f%2e%2e%2f%65%74%63 %2f%70%61%73%73%77%64
This request is made up of:
.%2e%2e%2f%2e%2e%2f%2e%2e%2f = ../../../
.%65%74%63 = etc
.%2f = /
.%70%61%73%73%77%64 = passwd
.
How would you protect from these attacks?
A.
Configure the Web Server to deny requests involving “hex encoded” characters
B.
Use SSL authentication on Web Servers
C.
Create rules in IDS to alert on strange Unicode requests
D.
Enable Active Scripts Detection at the firewall and routers
Explanation:
This is a typical Unicode attack. By configuring your IDS to trigger on strange Unicode requests you can protect your web-server from this type of attacks.