Daily Life - Something Trivial , Something Small : Vulnerability Information

Student security researcher Jing Wang from School of Physical and Mathematical Sciences at Nanyang Technological University, Singapore, has found new security vulnerabilities related to Yahoo.

After reporting several Open Redirect vulnerabilities to Yahoo. Yahoo’s responses were “It is working as designed”. It seems that Yahoo do not take the vulnerabilities seriously at all.

Based on Wang’s report on Full Disclosure “Multiple Open Redirect vulnerabilities were reported Yahoo. All Yahoo’s responses were “this intended behavior”. However, these vulnerabilities were patched later.“

The vulnerability of Yahoo occurs at “ard.yahoo.com” page. While the vulnerability of Yahoo Japan happens at sensitive page “http://order.store.yahoo.co.jp”.

Proof of concept on YouTube were also released to illustrate exploits.

(1)Yahoo Open Redirect
https://www.youtube.com/watch?v=k4eFLsTyZkg
(2)Yahoo Japan Unvalidated Redirects and Forwards (URF)
https://www.youtube.com/watch?v=2SM78WKAVr8

In fact, Yahoo’s users were attacked based on redirection this year. Base onCNET on January 4, 2014, “Yahoo.com visitors over the last few days may have been served with malware via the Yahoo ad network, according to Fox IT, a security firm in the Netherlands. Users visiting pages with the malicious ads were redirected to sites armed with code that exploits vulnerabilities in Java and installs a variety of different malware. ”

Wang wrote that the attack could work without a user being logged in. And his tests were using Firefox (33.0) in Ubuntu (14.04) and IE (10.0.9200.16521) in Windows 8.
Redirect can ensure a good user experience. However, if it is not properly provided. Attackers can use this to trick users. This is common in Phishing attacks and Spams.

On 21 December, 2014. Yahoo.com’s Alexa ranking is 4. While Yahoo.co.jp’s Alexa ranking is 17. Both of them are very popular around the world. From Wikipedia, “Yahoo during July 2013 surpassed Google on the number of United States visitors to its Web sites for the first time since May 2011, set at 196 million United States visitors, having increased by 21 percent in a year.”

Open redirect is listed in OWASP top 10. The general consensus of it is “avoiding such flaws is extremely important, as they are a favorite target of phishers trying to gain the user’s trust.”

CVE-2014-2230 - OpenX 2.8.10 Dest Redirect Privilege Escalation Web Security Vulnerability

Exploit Title: OpenX Dest Redirect Privilege Escalation Web Security Vulnerability
Product: OpenX
Vendor: OpenX
Vulnerable Versions: 2.8.10 and probably prior
Tested Version: 2.8.10
Advisory Publication: October 06, 2014
Latest Update: October 11, 2014
Vulnerability Type: URL Redirection to Untrusted Site ('Open Redirect') [CWE-601]
CVE Reference: *
Impact CVSS Severity (version 2.0):
CVSS v2 Base Score: 5.8 (MEDIUM) (AV:N/AC:M/Au:N/C:P/I:P/A:N) (legend)
Impact Subscore: 4.9
Exploitability Subscore: 8.6
CVSS Version 2 Metrics:
Access Vector: Network exploitable; Victim must voluntarily interact with attack mechanism
Access Complexity: Medium
Authentication: Not required to exploit
Impact Type: Allows unauthorized disclosure of information; Allows unauthorized modification
Writer and Reporter: Jing Wang [School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University (NTU), Singapore] (@justqdjing)

Caution Details:

(1) Vendor & Product Description:

Vendor:
OpenX

Product & Vulnerable Versions:
OpenX
2.8.10

Vendor URL & Download:
Product can be obtained from here,
http://openx.com/

Product Introduction Overview:
OpenX is a real time advertising technology company. The company has developed an integrated technology platform that combines ad server and a real time bidding (RTB) exchange with yield optimization for advertising and digital media companies. OpenX’s Ad Exchange is not only one of the world’s largest programmatic digital advertising exchanges. It’s the best performing marketplace with the highest-quality, independently-rated inventory. Building it was no small feat, and we were only able to do it because we understand that publishers’ primary goal with advertising is to optimize monetization. That means maximizing revenue and control, and our solution helps you do both. The first step in any high-performance marketplace is creating demand. Our real time auctions give you maximum exposure to demand sources. All of the largest DSPs, networks and agency trading desks, plus the top advertisers, already purchase inventory on OpenX’s Ad Exchange. We connect you to a broad and deep selection of buyers, and you choose which ones can bid and which impressions they can win. Once you have interested buyers, you want to be able to showcase your inventory and command the best price. Our Ad Exchange supports a variety of formats and screens, letting you easily make all of your inventory available on one platform. We also make it easy for you to extract the full value out of each impression. You can set price floors and employ whitelist and blacklist features to avoid channel conflict and potential dilution of relationships with advertisers who buy direct. Furthermore, you can utilize our technology to manage your premium inventory through direct relationships with advertisers by leveraging preferred deals and private auctions.

According to Pixelate, OpenX Marketplace has the highest quality ad inventory in 2015, beating Google's ad marketplace (Google Adx). OpenX integrations are widely distributed / long tail and currently sees the second most impressions on the internet, after Google. It's new traffic quality platform for viewability and fraud detection technology has ability to leverage this position by seeing impressions earlier than existing ad verification / pre-bid solutions used by DSP and agency trading desks. (a) OpenX was ranked the 3rd fastest growing software company in North America with 44,075% growth in revenues from 2008 - 2012 by Deloitte's Technology Fast 500. (b) According to a report from LeadLedger.com, OpenX has the second largest publisher adserver install base behind Google in 2013. (c) OpenX's current products include the OpenX Exchange, Ad Server, and SSP (supply side platform) with Demand Fusion. (d) 96% of top 100 brand advertisers and 58% of comScore 100 publishers work with OpenX, conducting 250 billion monthly transactions with 12 billion daily bids from buyers. All major demand side platforms (DSP) including Rocketfuel, Criteo, Turn, MediaMath, Invite Media and Appnexus buy from OpenX ad exchange.

(2) Vulnerability Details:
OpenX web application has a computer cyber security bug problem. It can be exploited by Unvalidated Redirects and Forwards (Open Redirect or URL Redirection) attacks. This could allow a user to create a specially crafted URL, that if clicked, would redirect a victim from the intended legitimate web site to an arbitrary web site of the attacker's choosing. Such attacks are useful as the crafted URL initially appear to be a web page of a trusted site. This could be leveraged to direct an unsuspecting user to a web page containing attacks that target client side software such as a web browser or document rendering programs.

Several other similar products 0-day vulnerabilities have been found by some other bug hunter researchers before. OpenX has patched some of them. The Full Disclosure mailing list is a public forum for detailed discussion of vulnerabilities and exploitation techniques, as well as tools, papers, news, and events of interest to the community. FD differs from other security lists in its open nature and support for researchers' right to decide how to disclose their own discovered bugs. The full disclosure movement has been credited with forcing vendors to better secure their products and to publicly acknowledge and fix flaws rather than hide them. Vendor legal intimidation and censorship attempts are not tolerated here! It also publishes suggestions, advisories, solutions details related to Open Redirect vulnerabilities and cyber intelligence recommendations.

Source code of adclick.php:
$destination = MAX_querystringGetDestinationUrl($adId[0]);
MAX_redirect($destination);

The "MAX_redirect" function is bellow,
function MAX_redirect($url)
{
if (!preg_match('/^(?:javascript|data):/i', $url)) {
header('Location: '.$url);
MAX_sendStatusCode(302);
}

The header() function sends a raw HTTP header to a client without any checking of the "$dest" parameter at all.

(1) For "adclick.php", the code programming flaw occurs with "&dest" parameter.

(2) For "ck.php", it uses "adclick.php" file. the code programming flaw occurs with "_maxdest" parameter.

(3) Solutions:
2014-10-12 Public disclosure with self-written patch.

References:

http://www.securityfocus.com/bid/70603

http://lists.openwall.net/full-disclosure/2014/10/16/1

https://www.mail-archive.com/fulldisclosure%40seclists.org/msg01216.html

http://marc.info/?l=full-disclosure&m=141343980308546&w=4
http://permalink.gmane.org/gmane.comp.security.fulldisclosure/1101

http://www.tetraph.com/blog/cves/cve-2014-2230-openx-open-redirect-vulnerability-2/

http://webcabinet.tumblr.com/post/116076640167/whitehatview-cve-2014-2230
http://diebiyi.com/articles/security/cves/cve-2014-2230-openx-open-redirect-vulnerability-2/
https://hackertopic.wordpress.com/2014/12/12/cve-2014-2230-openx
https://www.facebook.com/essaybeans/posts/479120835562721
http://ithut.tumblr.com/post/104660020768/whitehatview-cve-2014-2230-openx-dest-redirect
http://computerobsess.blogspot.com/2014/10/cve-2014-2230-openx-dest-redirect.html