(also input validation vulnerability)
An input validation attack is an unauthorized manual injection of harmful information into a standard user input field. The threat actor intentionally enters malicious data into the application or system to disrupt the system’s functionality. They use purposefully designed applications to perform input validation attacks. However, the breach is usually the result of an attacker corrupting the typical system behavior.
Buffer overflow. The malicious actor manipulates the coding errors and sends excessive information to the computer system. Such actions cause an overload and result in successful memory consumption, damage existing files, or expose data. The buffer overflow attack usually involves violating source code reliant on external data or too complex for the programmers to predict its behavior.
Canonicalization. In this type of cyberattack, a malicious user substitutes various inputs for the canonical name of a path or file. Files, paths, and URLs are sometimes unable to defend against canonicalization because many different characters can define the same inputs.
Cross-site scripting (XSS). It is a type of injection where malicious scripts are inserted into legitimate websites. For example, cybercriminals position harmful links along with valid URLs in seemingly innocent places, such as forums. Users cannot always distinguish between cyber threats and legitimate URLs and thus fall victim to a virus-infected ambush.
SQL injection. The hacker edits the URL by injecting malicious SQL code in the URL parameters to extract sensitive information that is not intended to be displayed.