Vulnerability – the lack of a computer system, the use of which lead to a breach of system integrity and malfunction. Vulnerabilities are caused by programming errors, shortcomings that allowed the design of the system, weak passwords, malware, scripting and SQL-injection.
The vulnerability allows an attacker to disrupt the correct operation of the application, for example, through the introduction of these unplanned way, run a command on the system that runs the application, or by using an omission that allows access to memory to run code on the privilege level of the program. Writing data to the buffer without checking its borders, resulting in a buffer overflow and the result is the execution of arbitrary code. It is also a vulnerability. As a result of the lack of validation of data entered by the user, there is a vulnerability that allows you to directly execute SQL (SQL-injection).
Vulnerabilities have been found in all major operating systems, including Microsoft Windows, Mac OS, UNIX and OpenVMS.