Final answer:
The phrase 'or'1'='1'--' is often used as a SQL injection attack to bypass authentication and gain unauthorized access to a web application.
Step-by-step explanation:
By entering the phrase 'or'1'='1'--' in a query, the attacker is attempting to exploit a vulnerability in the application's code that does not properly handle user input.
In this case, the attacker is using the 'or' operator and the condition '1=1' to always evaluate as true, allowing them to bypass any login checks and potentially gain access to sensitive data or perform unauthorized actions.
It is important for developers to properly sanitize and validate user input to prevent SQL injection attacks. This can be done by using parameterized queries and prepared statements, which ensure that user input is treated as data and not executable code.
By following secure coding practices and regularly updating software, web applications can mitigate the risk of SQL injection attacks and protect user data.