CyberGlossary

Attacks & Threats

Tailgating

Also known as: Door tailgating

Definition

A physical intrusion technique where an attacker slips through an access control by closely following an authorized person without their consent or awareness.

Tailgating is the practice of physically following an authorized employee through a secured door, turnstile, or barrier so that the attacker enters without presenting credentials. Unlike piggybacking, the legitimate user is typically unaware of the intruder or is pressured to ignore them. Attackers often blend in by wearing apparent uniforms, carrying boxes, or feigning a phone call. Once inside, they can plant rogue devices, steal documents, or pivot to network access. Countermeasures include mantraps, anti-tailgating sensors, security guards, badge enforcement, CCTV monitoring, and awareness campaigns that empower employees to challenge unfamiliar visitors politely.

Examples

  • An intruder walks closely behind an employee badging into a data centre and enters before the door closes.
  • An attacker wearing a fake contractor badge slips through a turnstile when the queue is busy.

Related terms