22-08-2012, 04:37 PM
Critical Network Security Issues
Critical Network Securityrahul.ppt (Size: 1.35 MB / Downloads: 49)
Introduction
Networking—IT’s “bag of worms”
Network security issues have traditionally been among the most difficult ones
Networking itself is complex
New network-related threats are constantly surfacing
New control measures (as well as “control pseudomeasures”) are commonplace
Networks (and networking itself) are constantly changing
What is a firewall?
In the most basic sense, a firewall is a security barrier between an internal and external network
External firewalls establish a “security perimeter”
Firewall serves as a choke point for incoming traffic
Dangerous incoming traffic is blocked
Is often a cost-effective method of defending
Systems within the perimeter
Networks and subnets
Recent changes in the firewall arena
Better performance and better central management capabilities, BUT
Firewalls are becoming increasingly vulnerable to
Direct attacks
Bypass of security mechanisms
Many firewall vulnerabilities are being found
“All-in-one” firewalls can increase risk considerably
The percentage of encrypted network traffic is increasing, but firewalls do not deal with encrypted traffic very well
Wireless networking vulnerabilities
“War driving” is now possible from relatively far away (up to 25 miles and even more)
Wired Equivalent Privacy (WEP), the most frequently used encryption protocol, is wide open to many types of attacks
Passive attacks--statistical analysis of WEP traffic
Active attacks (injecting new traffic, fooling the access point into accepting traffic it shouldn’t)
Dictionary-building attacks--based on analysis
Rogue wireless access points pose a serious problem
Spyware
Definition--hidden software and objects on systems such as cookies that send user information over the Internet to advertisers and others without the user's knowledge
Can
Force your browser to visit unwanted sites
Hijack e-mail
Modify browser and Registry settings in Windows systems
Force all outbound network traffic to go through a certain system before it arrives at its destination
Add or remove tools on menus
Much more…
Some Spyware is hidden incredibly well--in Windows systems you may see unknown applications such as Wub2jwu.exe running when you bring up the Task Manager, but when you examine your hard drive, you may not find them
Can be introduced into systems in many ways
Magnitude of problem is proliferating
Spyware, viruses and worms, and spam are becoming increasingly interconnected
Passwords
For decades passwords have been “low-hanging fruit” for
Attackers
Auditors
New password cracking tools (e.g., Rainbow Crack) are incredibly efficient
Attackers are increasingly planting keystroke loggers in systems