What kind of vulnerability does a deserialization attack exploit?

A deserialization attack primarily exploits vulnerabilities associated with the process of deserializing data that originates from untrusted sources. This type of attack occurs when an application processes serialized data (data that has been transformed into a format suitable for storage or transmission) without adequately verifying its integrity or authenticity.

When an application deserializes data, it reconstructs it into a usable object or structure. If the data being deserialized comes from an untrusted source, an attacker can manipulate this data to include malicious payloads. This malicious payload can lead to various vulnerabilities, such as remote code execution, data leakage, or bypassing application security mechanisms, as the application may execute unintended or harmful operations.

This type of vulnerability emphasizes the critical need for secure coding practices that validate and sanitize input before deserialization. Understanding this concept is pivotal for anyone involved in penetration testing or application security, as it highlights the risks associated with data handling.