2020/CVE-2020-24312/vultarget/wp-file-manager/classes/files-backup.php
<?php 
class wp_file_manager_files_backup {

    public function zipData($source, $destination) {
        if (extension_loaded('zip') === true) {
            if (file_exists($source) === true) {
                $zip = new ZipArchive();
                if ($zip->open($destination, ZIPARCHIVE::CREATE) === true) {
                    $source = realpath($source);
                    if (is_dir($source) === true) {
                        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);
                        foreach ($files as $file) {
                          if(strpos($file,'fm_backup') === false && (strpos($file,'opt') === false || strpos($file,'opt'))) {
                            $file = realpath($file);
                            if (is_dir($file) === true) {
                                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
                            } else if (is_file($file) === true) {
                                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
                            }
                          }
                        }
                    } else if (is_file($source) === true) {
                        $zip->addFromString(basename($source), file_get_contents($source));
                    }
                }
                return $zip->close();
            }
        }
        return false;
    }
    public function zipOther($source, $destination) {
        if (extension_loaded('zip') === true) {
            if (file_exists($source) === true) {
                $zip = new ZipArchive();
                if ($zip->open($destination, ZIPARCHIVE::CREATE) === true) {
                    $source = realpath($source);
                    if (is_dir($source) === true) {
                        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);                        
                        foreach ($files as $file) {     
                         if(strpos($file,'themes') === false && strpos($file,'uploads') === false && strpos($file,'plugins') === false){
                            $file = realpath($file);
                            if (is_dir($file) === true) {
                                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
                            } else if (is_file($file) === true) {
                                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
                            }
                         }

                        }
                    } else if (is_file($source) === true) {
                        $zip->addFromString(basename($source), file_get_contents($source));
                    }
                }
                return $zip->close();
            }
        }
        return false;
    }
}