Vulnerability scanning is a security technique used to identify security weaknesses in a computer system. Vulnerability scanning can be used by individuals or network administrators for security purposes. It can also be used by hackers attempting to gain unauthorized access to computer systems.

Vulnerability scanning can inadvertently result in computer crash. This may occur when the operating system views the vulnerability scan as invasive. Vulnerabilities can be discovered with a vulnerability scanner which analyzes a computer system in search of known vulnerabilities such as, open ports, susceptibility to malware infections, insecure software configurations etc. Also, antivirus software capable of heuristic analysis may discover undocumented malware if it finds software behaving in a suspicious manner.

Vulnerability scanners range from very expensive enterprise-level products to free open-source tools. Examples of vulnerability scanners include the following:

Port Scanner: Port scanner probes a server or host for open ports.

Network Enumerator: This is a computer program used to retrieve information about users and groups on networked computers.

Network Vulnerability Scanner: This is a system that proactively scans for network vulnerabilities.

Web Application Security Scanner: This scanner is a program that communicates with a Web application to find potential vulnerabilities within the application or its architecture.

Computer Worm: This is a type of self-replicated computer malware. It can also be used to find or detect vulnerabilities.