Definition
Tailgating, also known as piggybacking, is a physical security breach where an unauthorized person follows an authorized person into a restricted area. This often occurs when someone holds a door open for another person, either intentionally or unintentionally, allowing access to someone who should not have it. On a daily basis, it represents a significant vulnerability, as it bypasses many electronic access controls. For instance, an attacker might pose as a delivery person and wait for an employee to badge into a secure building, then slip in behind them. This differs from social engineering over the phone, which targets information rather than physical access. Tailgating is a common topic covered in cybersecurity certifications like CompTIA Security+ and CISSP.