# Exploit

A piece of code, technique, or sequence of commands that takes advantage of a software vulnerability to cause unintended behavior.

An **exploit[↗](/exploit)** is a piece of code, technique, or sequence of commands that takes advantage of a specific vulnerability[↗](/vulnerability) in software or hardware to cause unintended behavior, such as gaining unauthorized access, escalating privileges, or crashing a system. Exploits are the mechanism that turns a theoretical vulnerability into an actual attack.

Exploits are often bought, sold, and traded, with some fetching enormous prices on underground markets, particularly zero-day[↗](/zero-day) exploits for which no patch[↗](/patch) yet exists. Applying security patches promptly closes the vulnerabilities that exploits rely on, which is why patch management[↗](/patch-management) is such a core defense.