WordPress and Drupal Core Denial Of Service Vulnerability – Moderately Critical

Both WordPress and Drupal are affected by a DoS (denial of service) vulnerability on the PHP XML parser used by their XMLRPC implementations. The issue lies in the XML entity expansion parser that can cause CPU and memory exhaustion and the site’s database to reach the maximum number of open connections. That will cause the vulnerable site (and server) to go down for a period of time, hence affecting Availability of your website.

Kudos to the security teams from both platforms for their collaboration and synchronized disclosure.

The bug was discovered by Nir Goldshlager and disclosed on his blog at BreakSec. He goes onto to explain the specifics of the issue:

An XML quadratic blowup attack is similar to a Billion Laughs attack. Essentially, it exploits the use of entity expansion. Instead of deferring to the use of nested entities, it replicates one large entity using a couple thousand characters repeatedly.

A medium-sized XML document of approximately two hundred kilobytes may require anywhere within the range of one hundred MB to several GB of memory. When the attack is combined with a particular level of nested expansion, an attacker is then able to achieve a higher ratio of success.


If an attacker defines the entity “&x;” as 55,000 characters long, and refers to that entity 55,000 times inside the “DoS” element, the parser ends up with an XML Quadratic Blowup attack payload slightly over 200 KB in size, which expands to 2.5 GB when parsed.

WordPress and Drupal sites are vulnerable to this attack whether XML-RPC is used or not. This is not a vulnerability to be taken lightly. This also has large reaching impacts, any other applications leveraging a similar XMLRPC implementation is vulnerable.

Both projects, WordPress and Drupal, released an update today to address this problem and all users should upgrade asap to the latest version. Since this bug is trivial to exploit, we expect to see it in the wild very soon.

Because of the wide ranging impacts, it’s categorized as Moderately Critical. Any time Availability is affected, one of the pillars that makes up the Security triad, severity goes up. In this case, websites and web servers will go down. This emphasis on it being minor is incorrect, from a Security perspective.

Sucuri - Security Triad

Sucuri Customers Protected

Customer using our Website Firewall (CloudProxy) product are currently protected via our Virtual Patching. This will be especially useful for those that are running out of date versions of the platforms and are unable to update, hence making them susceptible to the attack.

Security issue on vBulletin’s uploader.swf

The vBulletin team recently disclosed a XSS (cross site scripting) vulnerability in the uploader.swf file that is included by default on vBulletin 4 and 5. This file comes from the YUI library that is not supported anymore, so the vBulletin team is recommending everyone to remove that file asap from their installs.

This is their full note:

It has come to our attention that there is a security issue in the uploader.swf file included as part of the Yahoo User Interface (YUI) library included in vBulletin 4. As the version of YUI included in vBulletin is end-of-lifed, Yahoo will not be fixing this issue.

We recommend that you replace this with an empty file of the same name (attached). What this will do is force vBulletin to use a fallback javascript based uploader which is already provided in your system.

The vulnerable file is also present in the vBulletin 5 download package though not used by the vBulletin 5 front-end. We recommend that you delete the file and replace it with the attached file.

To resolve this issue take the following steps:

-Delete uploader.swf located in clientscript/yui/uploader/assets or /core/clientscript/yui/uploader/assets
-Replace it with the attached file.

If you run vBulletin, please remove that file as soon as you can. Note that users of our CloudProxy website firewall are already protected against this threat.

Zero Day Vulnerability in OpenX Source 2.8.11 and Revive Adserver 3.0.1

If you are using OpenX or the new Revive Adserver (fork of OpenX), you need to update it ASAP. Florian Sander discovered a serious SQL injection vulnerability that affects all versions of OpenX and all versions of the Revive Adserver. From the Revive advisory:

An SQL-injection vulnerability was recently discovered and reported to the Revive Adserver team by Florian Sander.

The vulnerability is known to be already exploited to gain unauthorized access to the application using brute force mechanisms, however other kind of attacks might be possible and/or already in use. The risk is rated to be critical as the most common end goal of the attackers is to spread malware to the visitors of all the websites and ad networks that the ad server is being used on.

The vulnerability is also present and exploitable in OpenX Source 2.8.11 and earlier versions, potentially back to phpAdsNew 2.0.x.

The XML-RPC delivery invocation script was failing to escape its input parameters in the same way the other delivery methods do, allowing attackers to inject arbitrary SQL code via the “what” parameter of the delivery XML-RPC methods. Also, the escaping technique used to handle such parameter in the delivery scripts was based on the addslashes PHP function and has now been upgraded to use the dedicated escaping functions for the database in use.

We highly recommend anyone using OpenX to upgrade to the latest Revive version, or as a temporary fix, remove the file “www/delivery/axmlrpc.php” from your installation.

Clients using our CloudProxy Website Firewall are already protected against it. If you want to protect your OpenX / Revive install, you can sign up for CloudProxy here.

Server Update Time: OpenSSH Vulnerability Disclosed

The OpenSSH team just released a security advisory about a vulnerability affecting both OpenSSH 6.2 and 6.3.

If you are not familiar with OpenSSH, it’s the software used by a large majority of servers and hosting providers to provide SFTP and SSH services. Any vulnerability discovered in OpenSSH could have a major impact to website owners, and the Internet in general.

The good news is that this vulnerability only affects newer versions of OpenSSH, which are not widely used yet. If you are using Ubuntu 13.10 or Fedora 19, you are likely vulnerable. All other Linux distributions appears to be safe. To double check, log into your server via SSH and type the following command:

# sshd -h
OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010

If you see OpenSSH_6.2 or OpenSSH_6.3, you know you are using the affected versions.

Read More

OpenX.org Compromised and Downloads Injected with a Backdoor

We received reports that OpenX.org was compromised and the OpenX download files had a backdoor injected in them. According to Heise (in German), the malicious files were modified around November/2012, and have been undetected since.

It means that if you have downloaded OpenX during the last 7 months, it likely contains a backdoor that could allow the attackers full access to your site. That’s how serious it is.

*The OpenX team have confirmed the breach and removed the bad files from their servers.

Read More

New WordPress and Joomla Updates Available

If you are a WordPress or Joomla user, you better start updating your sites now.

Joomla 2.5.14

Joomla 2.5.14 was released containing some critical security fixes. They didn’t provide much details, but by the summary is seems serious enough to allow users to bypass upload restrictions:

Project: Joomla!
Severity: Critical
Versions: 2.5.13 and earlier 2.5.x versions. 3.1.4 and earlier 3.x versions.
Exploit type: Unauthorised Uploads
Reported Date: 2013-June-25
Fixed Date: 2013-July-31
Description: Inadequate filtering leads to the ability to bypass file type upload restrictions.

More information on Joomla 2.5.14 update here: http://developer.joomla.org/security/news/563-20130801-core-unauthorised-uploads

WordPress 3.6

WordPress 3.6 (a major release) was also announced with multiple new features and bug fixes. It doesn’t have any specific security fix, but keeping your site updated is a must, so we recommend all users to update.

More information on WordPress 3.6 is available here: http://codex.wordpress.org/Version_3.6

We recommend upgrading as soon as possible to reduce the risk of issue. Make sure you test your upgrades in a development environment before you go hot.

If you have any questions, feel free to drop an email.

Ubuntu Forums Hacked

Ubuntu’s official forum web site (ubuntuforums.org) was hacked, defaced and all user names and
passwords stolen. The forum was very popular with over 1.8 million registered users. The site is now disabled with this warning:

What we know:

-Unfortunately the attackers have gotten every user’s local username, password, and email address from the Ubuntu Forums database.

-The passwords are not stored in plain text. However, if you were using the same password as your Ubuntu Forums one on another service (such as email), you are strongly encouraged to change the password on the other service ASAP.

The site was running vBulletin and according to some sources, it was outdated and didn’t have the admin panel protected. During the time it was defaced, it was redirecting to “ubuntuforums.org/signaturepics/Sput.html”, which had this image:

Ubuntu forums hacked

Size of the attack and consequences

The Ubuntu forum was very large with over 1,800,000 registered members. Even though the passwords were not stored in plain text, they should be considered compromised and known by the attackers. And since the site used vBulletin, it is likely that they were just hashed with md5, which makes the job a lot easier to the attackers.

If you have an account there and you use the same password some where else, please
change the password asap.

Globo.com redirecting users to Spam ads

Globo.com, one of the largest Brazilian web portals (ranked #107 on Alexa and #6 for Brazilian traffic) appears to be compromised and all visits to it are being redirected to a sub page inside pagesinxt.com. If you go to g1.globo.com (or any other of their sub domains), you will end up on a page full of ads about Hosting, Internet and fake email products:

Globo.com redirection

That redirection has been going for a few hours at least and we detected it for the first time around 8am EST and it is still live four hours later (noon EST).

What is going on?

We are investigating, but at the bottom of any page inside google.com there is a script being loaded from sawpf.com:

<script defer src="httx://sawpf.com/1.0.js"></script>

That javascript file is being very slow to load, but when it does, it runs the following code:

 window.location = httx://pagesinxt.com/?dn=sawpf.com&fp=3WBUwymfgey…

Which forces the browser to redirect the to pagesinxt.com. At this point, we recommend all users to do not visit any globo.com page (or go there with Javascript disabled).

Who really owns your site?

This brings up a good topic that we brought up before. Who really owns your site? Every time you include a javascript (or widget or iframe), the security of your site becomes dependent on that third party server. It doesn’t looks like Globo in itself got compromised, but since they are including code from sawpf.com, they are only as secure as them.

Every time you add a remote JavaScript (or widget or iFrame) to your site, you are giving the server that houses that code full control of what is displayed to your users. If their servers get compromised, your site will be compromised as well.

Can you imagine if the author of the Easing Plugin was malicious? Instead of just that pop-up, they could have added a URL redirect to send all your users to any site they of their choosing (SPAM, porn, you name it). What if their server was hacked? The attackers could have added malware and it would have loaded to all your users.

*update 1: Lots of users on Twitter are complaining about it as well. Search for sawpf or pagesinxt to see the amount of people complaining or worried about it.

*update 2: If you click on some urls inside sawpf.com, you will be redirected to pagesinxt.com as well ( for example: httx://sawpf.com/libs/jquery/1.7.1.js )

Malaysian Election and DDOS

Malaysia is having an election this weekend that has been surrounded by issues. We won’t go into the politics, but one of our client’s sites (a popular Malaysian news source that we won’t name), started to suffer a very large scale DDOS (distributed denial of service attack). Reuters also has a similar story about another site and we can confirm what they are saying:

(Reuters) – Ahead of Malaysia’s elections on Sunday, independent online media say they are being targeted in Internet attacks which filter content and throttle access to websites, threatening to deprive voters of their main source of independent reporting.

This specific Malaysian site has been targeted for a couple of weeks, but since May 1st, their sites were hit by a very large botnet.

Malaysia site DDOS

To protect the innocent, we won’t go into much details, but the green in the graph is the outbound data and the blue is the inbound. And that means thousands of simultaneous connections per second being sustained for the last 4 days against them.

Technical details

This DDOS is httpd-based and is targeting their web server. It started by targeting their 404 handler by trying to visit pages that do not exist. What was interesting is the choice of URL they decided to use “FloodFloodFLOOD”: – - [01/May/2013:10:00:38 -0400] “GET /wp-content/uploads/2013/05/FloodFLOODFloodFLOOD.png HTTP/1.1″ 404

w – - [01/May/2013:10:00:38 -0400] “GET /wp-content/uploads/2013/05/FloodFLOODFloodFLOODFloodFLOODFLOOD.png HTTP/1.1″ 404 0 – - [01/May/2013:10:00:38 -0400] “GET /wp-content/uploads/2013/05/FloodFLOODFloodFLOODFloodFLOOD.png HTTP/1.1″ 404

That can be easily blocked and filtered, so they quickly switched to more complex types of attacks. Since the site is WordPress, they decided to target the search function to bypass any internal caches and make sure that each page is actually loaded: – - [02/May/2013:11:57:30 -0400] “GET /?s=1367683016682 HTTP/1.1″ 200 154 “http://www.erapasca.com/2013/05/pecah-berita-tanda-bn-nak-tumbang.html” “Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.56 Safari/537.36″ – - [02/May/2013:11:57:30 -0400] “GET /?s=1367683016683 HTTP/1.1″ 200 154 “http://www.erapasca.com/” “Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.56 Safari/537.36″ – - [02/May/2013:11:57:30 -0400] “GET /?s=1367682722241 HTTP/1.1″ 200 154 “http://www.erapasca.com/2013/05/pecah-berita-tanda-bn-nak-tumbang.html” “Mozilla/5.0 (Linux; Android 4.0.3; GT-P5100 Build/IML74K) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.169 Safari/537.22″ – - [02/May/2013:11:57:30 -0400] “GET /?s=1367682708689 HTTP/1.1″ 200 154 “http://siaranradioonline.blogspot.com/search/label/” “Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0; BOIE9;ENUS)”
.. thousands more per second ..

Notice that those referers and user agents are likely fake and just being used to try to bypass any security filter.

Size of the DDOS and their Botnet

What is actually impressive about this attack is the number of IP addresses (bots) being used. Just in the last 24 hrs, 36,367 (yes, 36 thousand different IP addresses ) were used to attack this site. It means that the people behind it have good power. What is interesting is that all IP addresses also come from Malaysian IP ranges and it seems to come from compromised desktops.

Since it is an ongoing event, we won’t give more details and we are working with the proper authorities and the Malaysian CERT to stop them.

Joomla 2.5.8 and 3.0.2 Released (Security Updates)

Joomla 2.5.8 and 3.0.2 were just released today fixing a medium severity security bug related to a clickjacking/XSS vulnerability. You can find more details on their release notes:

If you are not familiar with ClickJacking, Wikipedia explains it well:

Clickjacking is a malicious technique of tricking a Web user into clicking on something different to what the user perceives they are clicking on, thus potentially revealing confidential information or taking control of their computer while clicking on seemingly innocuous web pages. It is a browser security issue that is a vulnerability across a variety of browsers and platforms. A clickjack takes the form of embedded code or a script that can execute without the user’s knowledge, such as clicking on a button that appears to perform another function.

And remember, the leading cause for website compromises is outdated software! So as a website owner, you have to do your part to minimize risk and keep your site (and your users) safe. Update now!

Sucuri SiteCheck was also updated to alert users not running version 2.5.8/3.0.2 on their Joomla sites.