Showing posts with label URL Redirection. Show all posts
Showing posts with label URL Redirection. Show all posts

Friday, 5 June 2015

Google DoubleClicK System Bugs Could Be Used by Spammers



















Google DoubleClick.net (Advertising) System URL Redirection Vulnerabilities Could Be Used by Spammers



Although Google does not include Open Redirect vulnerabilities in its bug bounty program, its preventive measures against Open Redirect attacks have been quite thorough and effective to date.



However, Google might have overlooked the security of its DoubleClick.net ​advertising system. After some test, it is found that most of the redirection URLs within DoubleClick.net are vulnerable to Open Redirect vulnerabilities. Many redirection are likely to be affected. 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.



These redirections can be easily used by spammers, too.

Some URLs belong to Googleads.g.Doubleclick.net are vulnerable to Open Redirect attacks, too. While Google prevents similar URL redirections other than Googleads.g.Doubleclick.net. Attackers can use URLs related to Google Account to make the attacks more powerful.

Moreover, these vulnerabilities can be used to attack other companies such as Google, eBay, The New York Times, Amazon, Godaddy, Yahoo, Netease, e.g. by bypassing their Open Redirect filters (Covert Redirect). These cyber security bug problems have not been patched. Other similar web and computer attacks will be published in the near future.

Discover and Reporter:
Jing Wang, Division of Mathematical Sciences (MAS), School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University (NTU), Singapore. (@justqdjing)
http://www.tetraph.com/wangjing/




(1) Background Related to Google DoubleClick.net.


(1.1) What is DoubleClick.net?

"DoubleClick is a subsidiary of Google which develops and provides Internet ad serving services. Its clients include agencies, marketers (Universal McCann, AKQA etc.) and publishers who serve customers like Microsoft, General Motors, Coca-Cola, Motorola, L'Oréal, Palm, Inc., Apple Inc., Visa USA, Nike, Carlsberg among others. DoubleClick's headquarters is in New York City, United States.

DoubleClick was founded in 1996 by Kevin O'Connor and Dwight Merriman. It was formerly listed as "DCLK" on the NASDAQ, and was purchased by private equity firms Hellman & Friedman and JMI Equity in July 2005. In March 2008, Google acquired DoubleClick for US$3.1 billion. Unlike many other dot-com companies, it survived the dot-com bubble and focuses on uploading ads and reporting their performance." (Wikipedia)


(1.2) Reports Related to Google DoubleClick.net Used by Spammers



(1.2.1)

Google DoublClick.net has been used by spammers for long time. The following is a report in 2008.

"The open redirect had become popular with spammers trying to lure users into clicking their links, as they could be made to look like safe URLs within Google's domain."


(1.2.2)

Mitechmate published a blog related to DoubleClick.net spams in 2014.

"Ad.doubleclick.net is recognized as a perilous adware application that causes unwanted redirections when surfing on the certain webpages. Actually it is another browser hijacker that aims to distribute frauds to make money.Commonly people pick up Ad.doubleclick virus when download softwares, browse porn site or read spam email attachments. It enters into computer sneakily after using computer insecurely.Ad.doubleclick.net is not just annoying, this malware traces users’ personal information, which would be utilized for cyber criminal."


(1.2.3)

Malwarebytes posted a news related to DoubleClick.net malvertising in 2014.

"Large malvertising campaign under way involving DoubleClick and Zedo"




(2) DoubleClick.net System URL Redirection Vulnerabilities Details.

The vulnerabilities can be attacked without user login. Tests were performed on Microsoft IE (10.0.9200.16750) of Windows 8, Mozilla Firefox (34.0) & Google Chromium 39.0.2171.65-0 ubuntu0.14.04.1.1064 (64-bit) of Ubuntu (14.04),Apple Safari 6.1.6 of Mac OS X Lion 10.7.

Used webpages for the following tests. The webpage address is "http://securitypost.tumblr.com/". We can suppose that this webpage is malicious.



(2.1) Vulnerable URLs Related to Googleads.g.Doubleclick.net.


(2.1.1)

Some URLs belong to googleads.g.doubleclick.net are vulnerable to Open Redirect attacks. While Google prevents similar URL redirection other than googleads.g.doubleclick.net.

Vulnerable URLs:



POC:



Attackers can make use of the following URLs to make the attacks more powerful, i.e.



POC:



(2.1.2)

While Google prevents similar URL redirection other than googleads.g.doubleclick.net , e.g.





(2.2) Vulnerable URLs Related to DoubleClick.net.

Vulnerable URLs 1:



POC:




Vulnerable URLs 2:



POC:




Vulnerable URLs 3:



POC:




...



We can see that Google DoubleClick.net has Open Redirect vulnerabilities and could be misused by spammers.



(2.3)

POC Video:



Several other similar products 0-day vulnerabilities have been found by some other bug hunter researchers before. Google has patched some of them. BugTraq is a full disclosure moderated mailing list for the *detailed* discussion and announcement of computer security vulnerabilities: what they are, how to exploit them, and how to fix them. The below things be posted to the Bugtraq list: (a) Information on computer or network related security vulnerabilities (UNIX, Windows NT, or any other). (b) Exploit programs, scripts or detailed processes about the above. (c) Patches, workarounds, fixes. (d) Announcements, advisories or warnings. (e) Ideas, future plans or current works dealing with computer/network security. (f) Information material regarding vendor contacts and procedures. (g) Individual experiences in dealing with above vendors or security organizations. (h) Incident advisories or informational reporting. (i) New or updated security tools. A large number of the fllowing web securities have been published here, Buffer overflow, HTTP Response Splitting (CRLF), CMD Injection, SQL injection, Phishing, Cross-site scripting, CSRF, Cyber-attack, Unvalidated Redirects and Forwards, Information Leakage, Denial of Service, File Inclusion, Weak Encryption, Privilege Escalation, Directory Traversal, HTML Injection, Spam. It also publishes suggestions, advisories, solutions details related to Open Redirect vulnerabilities and cyber intelligence recommendations.




(3) Google DoubleClick.net Can Adversely Affect Other Websites.

At the same time, Google DoubleClick.net can be used to do "Covert Redirect" to other websites, such as Google, eBay, The New York Times, etc.(Bypass other websites' Open Redirect filters)



(3.1) Google Covert Redirect Vulnerability Based on Googleads.g.doubleclick.net


Domain:
google.com


"Google is an American multinational technology company specializing in Internet-related services and products. These include online advertising technologies, search, cloud computing, and software. Most of its profits are derived from AdWords, an online advertising service that places advertising near the list of search results. Google was founded by Larry Page and Sergey Brin while they were Ph.D. students at Stanford University. Together they own about 14 percent of its shares but control 56 percent of the stockholder voting power through supervoting stock. They incorporated Google as a privately held company on September 4, 1998. An initial public offering followed on August 19, 2004. Its mission statement from the outset was "to organize the world's information and make it universally accessible and useful," and its unofficial slogan was "Don't be evil". In 2004, Google moved to its new headquarters in Mountain View, California, nicknamed the Googleplex. The corporation has been estimated to run more than one million servers in data centers around the world (as of 2007). It processes over one billion search requests and about 24 petabytes of user-generated data each day (as of 2009). In December 2013, Alexa listed google.com as the most visited website in the world. Numerous Google sites in other languages figure in the top one hundred, as do several other Google-owned sites such as YouTube and Blogger. Its market dominance has led to prominent media coverage, including criticism of the company over issues such as search neutrality, copyright, censorship, and privacy." (Wikipedia)


Vulnerable URL:

POC:


More Details:

Video:

Blog:



(3.2) eBay Covert Redirect Vulnerability Based on Googleads.g.doubleclick.net


Domain:
ebay.com

"eBay Inc. (stylized as ebay) is an American multinational corporation and e-commerce company, providing consumer to consumer & business to consumer sales services via Internet. It is headquartered in San Jose, California, United States. eBay was founded by Pierre Omidyar in 1995, and became a notable success story of the dot-com bubble. Today, it is a multi-billion dollar business with operations localized in over thirty countries. The company manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide. In addition to its auction-style sales, the website has since expanded to include "Buy It Now" shopping; shopping by UPC, ISBN, or other kind of SKU (via Half.com); online classified advertisements (via Kijiji or eBay Classifieds); online event ticket trading (via StubHub); online money transfers (via PayPal) and other services. It is not a free website, but charges users an invoice fee when sellers have sold or listed any items." (Wikipedia)



Vulnerable URL:

POC:


More Details:

Video:

Blog:



(3.3) The New York Times (Nytimes.com) Covert Redirect Vulnerability Based on Google Doubleclick.net


Domain:
nytimes.com


"The New York Times (NYT) is an American daily newspaper, founded and continuously published in New York City since September 18, 1851, by the New York Times Company. It has won 114 Pulitzer Prizes, more than any other news organization. The paper's print version has the largest circulation of any metropolitan newspaper in the United States, and the second-largest circulation overall, behind The Wall Street Journal. It is ranked 39th in the world by circulation. Following industry trends, its weekday circulation has fallen to fewer than one million daily since 1990. Nicknamed for years as "The Gray Lady", The New York Times is long regarded within the industry as a national "newspaper of record". It is owned by The New York Times Company. Arthur Ochs Sulzberger, Jr., (whose family (Ochs-Sulzberger) has controlled the paper for five generations, since 1896), is both the paper's publisher and the company's chairman. Its international version, formerly the International Herald Tribune, is now called the International New York Times." (Wikipedia)


Vulnerable URL:

POC:


More Details:

Video:

Blog:




These vulnerabilities were reported to Google earlier in 2014. But it seems that Google has yet taken any actions. All of the vulnerabilities are still not patched.









Related Posts:
https://cxsecurity.com/issue/WLB-2014110106
http://permalink.gmane.org/gmane.comp.security.fulldisclosure/1192
https://www.mail-archive.com/fulldisclosure%40seclists.org/msg01307.html
http://computerobsess.blogspot.com/2014/11/google-doubleclicknetadvertising-system.html
http://www.techenet.com/2014/12/doubleclick-do-google-pode-ser-vulneravel-a-ataques/
https://computertechhut.wordpress.com/2014/11/12/google-doubleclick-spam/
http://mathpost.tumblr.com/post/120760828940/tetraph-google-doubleclick-net-advertising
http://tetraph.com/security/open-redirect/google-doubleclick-netadvertising-system
https://www.facebook.com/essayjeans/posts/838922772865543
https://plus.google.com/u/0/+essayjeans/posts/Y12x6gXfyFX
http://mathstopic.blogspot.com/2015/06/google-doubleclick-spam.html
http://itsecurity.lofter.com/post/1cfbf9e7_72fe79f
https://twitter.com/essayjeans/status/606726247578636288
http://tetraph.tumblr.com/post/120760676767/google-doubleclick-net-advertising
https://itinfotechnology.wordpress.com/2014/11/18/google-doubleclick-spam/
https://www.facebook.com/permalink.php?story_fbid=945171075538075
http://guyuzui.lofter.com/post/1ccdcda4_7305f25
http://tetraph.blog.163.com/blog/static/23460305120155534216326/
http://www.inzeed.com/kaleidoscope/spamming/google-doubleclick-spam/







Friday, 15 August 2014

Paypal Online Website OAuth 2.0 Covert Redirect (OpenIDconnect) Web Security Bugs (Information Leakage & Open Redirect)




 














Paypal Online Website OAuth 2.0 Covert Redirect (OpenIDconnect) Web Security Bugs (Information Leakage & Open Redirect)



(1) Domain:
paypal.com


"PayPal is an American worldwide online payments system. Online money transfers serve as electronic alternatives to traditional paper methods like checks and money orders. PayPal is one of the world's largest internet payment companies.The company operates as an acquirer, performing payment processing for online vendors, auction sites and other commercial users, for which it charges a fee. 
Established in 1998, PayPal (NASDAQ: PYPL) had its IPO in 2002, and became a wholly owned subsidiary of eBay later that year. In 2014, PayPal moved $228 billion in 26 currencies across more than 190 nations, generating a total revenue of $7.9 billion (44% of eBay’s total profits). The same year, eBay announced plans to spin-off PayPal into an independent company the following year." (Wikipedia)







(2) Vulnerability Description:

Paypal web application has a computer security problem. Hacker can exploit it by Covert Redirect cyber attacks. 


The vulnerabilities can be attacked without user login. Tests were performed on Microsoft IE (10.0.9200.16750) of Windows 8, Mozilla Firefox (34.0) & Google Chromium 39.0.2171.65-0 ubuntu0.14.04.1.1064 (64-bit) of Ubuntu (14.04),Apple Safari 6.1.6 of Mac OS X Lion 10.7. 












(2.1) Vulnerability Detail:

PayPal's OAuth 2.0 system is susceptible to Attacks. More specifically, the authentication of parameter "&redirct_uri" in OAuth 2.0 system is insufficient. It can be misused to design Open Redirect Attacks to PayPal.


At the same time, it can be used to collect sensitive information of both third-party app and users by using the following parameters,
"&response_type"=code,token...
"&scope"=email,user_birthday,user_likes...




It increases the likelihood of successful Open Redirect Attacks to third-party websites, too.


The vulnerability occurs at page "/openidconnect/v1/authorize?" with parameter "&redirect_uri", e.g.





Before acceptance of third-party application:
When a logged-in PayPal user clicks the URL ([1]) above, he/she will be asked for consent as in whether to allow a third-party website to receive his/her information. If the user clicks OK, he/she will be then redirected to the URL assigned to the parameter "&redirect_uri".


If a user has not logged onto PayPal and clicks the URL ([1]) above, the same situation will happen upon login.



After acceptance of third-party application:
A logged-in PayPal user would no longer be asked for consent and could be redirected to a webpage controlled by the attacker when he/she clicks the URL ([1]).


For a user who has not logged in, the attack could still be completed after a pop-up page that prompts him/her to log in.






(2.1.1) PayPal would normally allow all the URLs that belong to the domain of an authorized third-party website. However, these URLs could be prone to manipulation. For example, the "&redirect_uri" parameter in the URLs is supposed to be set by the third-party websites, but an attacker could change its value to make Attacks. 

Hence, a user could be redirected from PayPal to a vulnerable URL in that domain first and later be redirected from this vulnerable site to a malicious site unwillingly. This is as if the user is redirected from PayPal directly. The number of PayPal's OAuth 2.0 client websites is so huge that such Attacks could be commonplace.

Before acceptance of the third-party application, PayPal's OAuth 2.0 system makes the redirects appear more trustworthy and could potentially increase the likelihood of successful Open Redirect Attacks of third-party website.

Once the user accepts the application, the attackers could completely bypass PayPal's authentication system and attack more easily.

It might be of PayPal's interest to patch up against such attacks. 




(2.2) Used one of webpages for the following tests. The webpage is "http://essayjeanslike.lofter.com/". Can suppose it is malicious and contains code that collect sensitive information of both third-party app and users.



Below is an example of a vulnerable third-party domain:



Vulnerable URL in this domain:

Vulnerable URL from PayPal that is related to constantcontact.com:

POC:







POC Video:
https://www.youtube.com/watch?v=TVtLA1YzIBs


Blog Detail:
http://tetraph.blogspot.com/2014/05/paypal-oauth-20-openidconnect-covert.html






(3) What is Covert Redirect? 


Covert Redirect is a class of security bugs disclosed in May 2014. It is an application that takes a parameter and redirects a user to the parameter value without sufficient validation. This often makes use of Open Redirect and XSS (Cross-site Scripting) vulnerabilities in third-party applications.



Covert Redirect is also related to single sign-on. It is known by its influence on OAuth and OpenID. Hacker may use it to steal users' sensitive information. Almost all OAuth 2.0 and OpenID providers worldwide are affected. Covert Redirect can work together with CSRF (Cross-site Request Forgery) as well.






Discover and Reporter:
Wang Jing, Division of Mathematical Sciences (MAS), School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University (NTU), Singapore. (@justqdjing)










Related Articles:
http://tetraph.com/security/covert-redirect/paypal-oauth-2-0-openidconnect-covert-redirect-vulnerability/
http://ithut.tumblr.com/post/119493112323/securitypost-sicherheitslucke-in-oauth-2-0-und
https://twitter.com/tetraphibious/status/559164333721001984
http://www.inzeed.com/kaleidoscope/covert-redirect/paypal-oauth-2-0-openidconnect-covert-redirect-vulnerability/
http://computerobsess.blogspot.sg/2014/05/paypal-bug.html
https://hackertopic.wordpress.com/2014/05/01/paypal-covert-redirect/
http://ittechnology.lofter.com/post/1cfbf60d_72e61e0
http://securityrelated.blogspot.com/2014/05/paypal-bug.html
http://blog.163.com/tetraph/blog/static/23460305120144612635422
https://webtechwire.wordpress.com/2014/05/02/paypal-covert-redirect/