validate_file( string $file, string[] $allowed_files = array() )
Validates a file name and path against an allowed set of rules.
Description
A return value of 1
means the file path contains directory traversal.
A return value of 2
means the file path contains a Windows drive path.
A return value of 3
means the file is not in the allowed files list.
Parameters
- $file
-
(string) (Required) File path.
- $allowed_files
-
(string[]) (Optional) Array of allowed files.
Default value: array()
Return
(int) 0 means nothing is wrong, greater than 0 means something was wrong.
Source
File: wp-includes/functions.php
function validate_file( $file, $allowed_files = array() ) { // `../` on its own is not allowed: if ( '../' === $file ) { return 1; } // More than one occurence of `../` is not allowed: if ( preg_match_all( '#\.\./#', $file, $matches, PREG_SET_ORDER ) && ( count( $matches ) > 1 ) ) { return 1; } // `../` which does not occur at the end of the path is not allowed: if ( false !== strpos( $file, '../' ) && '../' !== mb_substr( $file, -3, 3 ) ) { return 1; } // Files not in the allowed file list are not allowed: if ( ! empty( $allowed_files ) && ! in_array( $file, $allowed_files, true ) ) { return 3; } // Absolute Windows drive paths are not allowed: if ( ':' === substr( $file, 1, 1 ) ) { return 2; } return 0; }
Changelog
Version | Description |
---|---|
1.2.0 | Introduced. |
© 2003–2021 WordPress Foundation
Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/validate_file