The Application Level Program Providing the Service

The Application Level Program Providing the Service

Network applications can be vulnerable to denial of service attacks in
the same way that operating systems are. If no allowances are made for
unexpected traffic or other input, the application could encounter a
condition where it hangs, and can no longer provide the service it was
designed for. Poor error handling in the code could lead to the same
result.
If the operating system does not take adequate precautions for extreme
conditions, it could be vulnerable to an attack that attempts to exhaust
the physical resources available on the system. Several such attacks
have been released which push the CPU to 100 percent utilization, and
thereby deny access to other services.
Distributed Denial of Service (DDoS) Attacks
Otherwise known as DDoS, these attacks have the same goal as
standard Denial of Service attacks but use a different architecture in
achieving it. A single host launching a network or application level
attack against a target is constrained by it's own available network
bandwidth and system resources, a group of machines can be more
effective in a concerted attack. The current DDoS programs publicly
available all use the same basic architecture to control the attack,
common examples being:
• Stacheldraht.
• TFN.
• TFN2K.