protected static function PhpMail::_isShellSafe in Drupal 9

Same name and namespace in other branches

1. 8 core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php \Drupal\Core\Mail\Plugin\Mail\PhpMail::_isShellSafe()
2. 10 core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php \Drupal\Core\Mail\Plugin\Mail\PhpMail::_isShellSafe()

Disallows potentially unsafe shell characters.

Functionally similar to PHPMailer::isShellSafe() which resulted from CVE-2016-10045. Note that escapeshellarg and escapeshellcmd are inadequate for this purpose.

@todo Rename to ::isShellSafe() and/or discuss whether this is the correct location for this helper.

Parameters

string $string: The string to be validated.

Return value

bool True if the string is shell-safe.

See also

https://github.com/PHPMailer/PHPMailer/issues/924

https://github.com/PHPMailer/PHPMailer/blob/v5.2.21/class.phpmailer.php#...

1 call to PhpMail::_isShellSafe()

PhpMail::mail in core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php

Sends an email message.

File

core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php, line 164

Class

PhpMail

Defines the default Drupal mail backend, using PHP's native mail() function.

Namespace

Drupal\Core\Mail\Plugin\Mail

Code

protected static function _isShellSafe($string) {
  if (escapeshellcmd($string) !== $string || !in_array(escapeshellarg($string), [
    "'{$string}'",
    "\"{$string}\"",
  ])) {
    return FALSE;
  }
  if (preg_match('/[^a-zA-Z0-9@_\\-.]/', $string) !== 0) {
    return FALSE;
  }
  return TRUE;
}