A security breach is any incident that results in unauthorized access of data, applications, services, networks and/or devices by bypassing their underlying security mechanisms. A security breach occurs when an individual or an application illegitimately enters a private, confidential or unauthorized logical IT perimeter.
A security breach is one of the earliest stages of a security attack by a malicious intruder, such as a hacker, cracker or nefarious application. Security breaches happen when the security policy, procedures and/or system are violated. Depending on the nature of the incident, a security breach can be anything from low-risk to highly critical.
In an organization, security breaches are typically monitored, identified and mitigated by a software or hardware firewall. If an intrusion, abnormality or violation is detected, the firewall issues a notification to the network or security administrator.
