What are the potential pitfalls of relying on register_globals and magic_quotes_gpc in PHP code?

Relying on register_globals can lead to security vulnerabilities as it allows external input to overwrite global variables, potentially leading to injection attacks. Magic_quotes_gpc, on the other hand, can cause data to be improperly escaped, leading to data corruption or SQL injection vulnerabilities. It is recommended to disable both of these features and instead use superglobal arrays like $_GET, $_POST, and $_REQUEST to access user input securely.

// Disable register_globals in php.ini
register_globals = Off;

// Disable magic_quotes_gpc in php.ini
magic_quotes_gpc = Off;