A single vulnerability can have multiple exploits and the most common defenses target exploits, not vulnerabilities as shown in the following figure:

It possess the following characteristics:

• Exploits are commercial offerings:
  • Prices follow ordinary market rules of supply and demand
• Available in the underground as well and as from established vendors
• Procured by different types of customers, such as hacktivists, cyber criminals, organizations, and governments
• Utilized for targeted and broad attacks