F2blog XMLRPC 上传任意文件漏洞

原作者: [db:作者] 来自: [db:来源] 收藏邀请

刚从官方下载的最新版：F2blog-v1.2_build_03.01_full 存在漏洞文件：xmlrpc.php，
影响：可上传任意文件到服务器。
原理：get_http_raw_post_data()是获取最原始的传递过来的数据，也是说不会因为PHP环境的magic为on的影响。
而他在check_user_pw的时候，并没有过滤，结合后面的上传没有做后缀判断，所有可以直接导致上传任意文件到服务器。简单分析：
function metaWeblog_newMediaObject ($values) { //2007-02-01 add support for uploading files
global $settingInfo,$DMC, $DBPrefix,$defualtcategoryid;
//此处本是判断用户是否登录的，但是下面没有做检查，仅仅在这里返回了用户是否登录的一个值。
$userdetail = check_user_pw ($values['username'], $values['password']); $struct=$values['struct'];
//writetofile ('text1.php', $struct['bits']); //debug only
if ($struct['bits'] && $struct['name']) {
$writefilecontent=base64_decode($struct['bits']);
if (file_exists("attachments/{$struct['name']}")) @unlink("attachments/{$struct['name']}");

$filenum=@fopen("attachments/{$struct['name']}","wb");
if (!$filenum) {
xml_error ("Sorry, uploading file ({$struct['name']}) failed.");
}
flock($filenum,LOCK_EX);
fwrite($filenum,$writefilecontent);
//并没有判断文件是否安全，直接写入。
fclose($filenum);
}
$xml_content=make_xml_piece ("struct", array('url'=>"{$settingInfo['blogurl']}/attachments/{$struct['name']}"));
$body_xml=xml_generate($xml_content);
send_response ($body_xml);
}
本来说到这里都够明白了，下面就再把利用方法写下吧：
定义的方法数组：
$methodFamily=array('blogger.newPost', 'blogger.editPost', 'blogger.getUsersBlogs', 'blogger.getUserInfo', 'blogger.deletePost', 'blogger.getTemplate', 'blogger.setTemplate', 'metaWeblog.newPost', 'metaWeblog.editPost', 'metaWeblog.getPost', 'metaWeblog.newMediaObject', 'metaWeblog.getCategories', 'metaWeblog.getRecentPosts');
方法调用：
$methodName=parse_get($rawdata, 'methodName', true);
if (!@in_array($methodName, $methodFamily)) xml_error ("Method ({$methodName}) is not availble.");
$values=parse_get($rawdata, 'value'); $values=parse_walk_array($values, $methodName);
//print_r($values); //For debug only
//exit();
//Get default category, for those editors which don't support Categories
$sql="select * from ".$DBPrefix."categories limit 0,1";
$arr_category=$DMC->fetchArray($DMC->query($sql));
$defualtcategoryid=$arr_category[id]; $methodName=str_replace('.', '_', $methodName);
call_user_func ($methodName, $values);
$rawdata的来源：
$rawdata=get_http_raw_post_data();
//writetofile ("text4.xml", $rawdata); //For debug use
//$rawdata=file_get_contents("text4.xml"); //For debug use if (!$rawdata) die ("Sorry, don't visit this web!"); $stringType_o="i4|int|boolean|struct|string|double|base64|dateTime\.iso8601";
$stringType="(".$stringType_o.")"; $rawdata=str_replace("\r", '', $rawdata);
$rawdata=str_replace("\n", '', $rawdata);
$rawdata=str_replace("\t", '', $rawdata);
$rawdata=str_replace("<![CDATA[", '', $rawdata);
$rawdata=str_replace("]]>", '', $rawdata); //Stupid CDATA, I don't want it
$rawdata=preg_replace("/<([^>] ?) \/>/is", '<\\1></\\1>', $rawdata); //Self-closed tags
//$rawdata=convert_utf8($rawdata); $rawdata=preg_replace_callback("/<struct>(. ?)<\/struct>/is", 'filter_struct', $rawdata); //Struct can be a trouble, use this to avoid values and names being parsed
get_http_raw_post_data()方法：
function get_http_raw_post_data () { //Get http_raw_post_data
global $HTTP_RAW_POST_DATA;
if (isset($HTTP_RAW_POST_DATA)) { //Good, the server supports $HTTP_RAW_POST_DATA, then return it directly
return trim($HTTP_RAW_POST_DATA);
}
elseif (PHP_OS>="4.3.0") { //PHP 4.3.0 and higher version supports another way to get it
return readfromfile( 'php://input' );
}
else return false; //Sorry, no way out, or $raw data is not set at all
} 漏洞修补，简单点的，判断下用户是否有上传附件的权限。其他的自己发挥吧。
既然费了这么多话，那就顺便附上一个安全点的方法吧：
function metaWeblog_newMediaObject ($values) { //2008-05-27 edit by Neeao
global $settingInfo,$DMC, $DBPrefix,$defualtcategoryid;
$userdetail = check_user_pw ($values['username'], $values['password']); $records=$DMC->fetchArray($DMC->query("SELECT * FROM `{$DBPrefix}logs` WHERE `id`='{$values['postid']}'"));
if ($records['id']=='') xml_error ("Entry does not exist.");
else {
$struct=$values['struct'];
//writetofile ('text1.php', $struct['bits']); //debug only
if ($struct['bits'] && $struct['name']) {
$writefilecontent=base64_decode($struct['bits']);
if (file_exists("attachments/{$struct['name']}")) @unlink("attachments/{$struct['name']}");

$filenum=@fopen("attachments/{$struct['name']}","wb");
if (!$filenum) {
xml_error ("Sorry, uploading file ({$struct['name']}) failed.");
}
flock($filenum,LOCK_EX);
fwrite($filenum,$writefilecontent);
fclose($filenum);
}
$xml_content=make_xml_piece ("struct", array('url'=>"{$settingInfo['blogurl']}/attachments/{$struct['name']}"));
$body_xml=xml_generate($xml_content);
send_response ($body_xml);
}
}
没有加文件格式的判断，有点麻烦了，懒得写了。