How to enable allow_url_fopen functions?

Security Implications

If enabled, allow_url_fopen allows PHP's file functions -- such as file_get_contents() and the include and require statements -- can retrieve data from remote locations, like an FTP or web site. Programmers frequently forget this and don't do proper input filtering when passing user-provided data to these functions, opening them up to code injection vulnerabilities. A large number of code injection vulnerabilities reported in PHP-based web applications are caused by the combination of enabling allow_url_fopen and bad input filtering.

allow_url_fopen is off by default.

 

Recommendations

 

You should enable allow_url_fopen in the php.ini file:

; Disable allow_url_fopen for security reasons
allow_url_fopen = 'on'

The setting can also be enable in .htaccess file:

# Disable allow_url_fopen for security reasons
php_flag  allow_url_fopen  on

For remote file access, consider using the cURL functions that PHP provides.