F2blog XMLRPC 上传任意文件漏洞

By:Maple-x[B.C.T]
Site:http://www.neeao.com
Date:2008-5-27

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

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']}");

[email protected]("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 ([email protected]_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']}");

[email protected]("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。

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