Cisco Cisco ASA 5525-X Adaptive Security Appliance 白書

 

 

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©Nemertes Research 2008 

security relationship continues to grow.  More outsiders need access to more 
services year by year. If a separate DMZ has to be spawned for each partner, 

customer, or supplier to which the enterprise needs to grant specialized access to 
specific internal services, the number of DMZs can quickly grow from the 

manageable to the ridiculous. The static associations such structures imply make 

sense in a world where resources are stationary and separable, but is 
incompatible with the flexible data center and its increasingly interdependent 
resources.  

Organizations want to ensure that they can respond to changes in their 

markets and deploy new applications rapidly.  With such IT agility as a strategic 
focus, reliance on static barriers for security will make the infrastructure less 
flexible, and therefore, make the business less agile.

 

Agility is a critical 

competitive advantage which should not be sacrificed because of security. 

Consequently, companies implementing SOA and virtualization for agility must 
likewise adopt agile security to match.

 

The changeable nature of the new data center is only part of the problem 

for security, of course.  Another major part of the problem is the shift in 

application and attack focus up the network stack.   

Although attacks at layers two through four are still active and dangerous, 

security at those levels is also relatively strong and increasingly ubiquitous.  
However, security on layers five through seven lags.  At the same time, enterprise 

applications are rapidly changing in both back-end architecture and front-end 
implementations. The move to SOA drives applications to swap internal or binary 

communications for externalized XML interchanges. The move to unified 
communications puts SIP into the center of converged and integrated voice and 
data systems.  

Enterprise operations are now being driven by XML documents, SIP 

sessions, SOAP objects, and the like, and this exposes the enterprise to attacks 
based on those formats and on the content conveyed within them.  Criminals now 

aim attacks at compromising parsers for any or all of these formats, hoping to 
break into the system hosting an application by feeding it poisoned content in the 
same way they once sought to crash or compromise routers by feeding them 
carefully malformed packets. They might also seek to compromise an enterprise 

not by breaking into or taking control of a system but instead by using systems 
for their defined purposes but towards bogus ends: in a SOA based inventory 
system, for example, well-formed but bogus purchase orders created by criminals 
could empty a warehouse and send millions of dollars worth of goods to random 

or non-existent addresses.  And the back end is only part of the problem: Web 2.0 

front ends carry some of the same problems into the client side of the picture, as 
XML traffic drives the content of client interfaces.  Corrupting or hijacking those 
streams could effect anything from a simple denial of service to password theft,  
data theft, or operational sabotage.