Exploit

A piece of code or technique that takes advantage of a specific software or hardware weakness to make a system behave in a way its designers did not intend.

A vulnerability is a weakness; an exploit is the method of using it. Exploits can allow attackers to run their own code on a computer, bypass logins, gain administrator rights or crash a service. Once an exploit for a widely used product is published or sold, criminals often begin scanning the internet for vulnerable systems within days or even hours.

Small businesses are frequently hit by exploits of known flaws that already have fixes available, simply because updates were not applied. Firewalls, VPN appliances, email servers and remote access tools that face the internet are especially common targets. A zero-day exploit, which targets a flaw with no available fix yet, is less common but harder to defend against.

Practical tip: prioritize updates for internet-facing systems and apply critical security patches as quickly as you reasonably can. Subscribe to alerts from your key vendors, or rely on your IT provider to track advisories from sources such as the Canadian Centre for Cyber Security.