Adversaries may attempt to take advantage of a weakness in an internet-facing computer or program using software, data or commands in order to cause unintended or unanticipated behavior. The weakness in the system can be a bug, a glitch, or a design vulnerability. These applications are often websites, but can include databases (like SQL), standard services (like SMB or SSH), network device administration and management protocols (like SNMP and Smart Install), and any other applications with Internet accessible open sockets, such as web servers and related services. Depending on the flaw being exploited this may include an Exploitation for Defense Evasion.
If an application is hosted on cloud-based infrastructure, then exploiting it may lead to compromise of the underlying instance. This can allow an adversary a path to access the cloud APIs or to take advantage of weak identity issues and access the management policies.
For websites and databases, the OWASP top 10 and CWE top 25 highlight the most common web-based vulnerabilities.