validate_file( string $file, array $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
-
(Required) File path.
- $allowed_files
-
(Optional) List 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 ) )
return 3;
// Absolute Windows drive paths are not allowed:
if (':' == substr( $file, 1, 1 ) )
return 2;
return 0;
}
Changelog
| Version | Description |
|---|---|
| WP-1.2.0 | Introduced. |