Language: PHP
Label: safe
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
    public function flush($config)
    {
        if (!$this->_prepareDir($config)) {
            return false;
        }
        $dir = $this->generateDirectoryPath($config);
        $dh = opendir($dir);
        // Apparently, on some versions of PHP, readdir will return
        // an empty string if you pass an invalid argument to readdir.
        // So you need this test.  See #49.
        if (false === $dh) {
            return false;
        }
        while (false !== ($filename = readdir($dh))) {
            if (empty($filename)) {
                continue;
            }
            if ($filename[0] === '.') {
                continue;
            }
            unlink($dir . '/' . $filename);
        }
        closedir($dh);
        return true;
    }