eBay Covert Redirect Vulnerability Based on Googleads.g.doubleclick.net
(1) WebSite: ebay.com
“eBay Inc. (stylized as ebay, formerly 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. 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.” (Wikipedia)
(2) Vulnerability Description:
eBay web application has a computer cyber security problem. Hacker can exploit it by Covert Redirect attacks.
The vulnerability occurs at “ebay.com/rover” page with “&mpre” parameter, i.e.
The vulnerability can be attacked without user login. Tests were performed on Firefox (26.0) in Ubuntu (12.04) and IE (9.0.15) in Windows 7.
(2.1) When a user is redirected from eBay to another site, eBay will check whether the redirected URL belongs to domains in eBay’s whitelist, e.g.
If this is true, the redirection will be allowed.
However, if the URLs in a redirected domain have open URL redirection vulnerabilities themselves, a user could be redirected from eBay to a vulnerable URL in that domain first and later be redirected from this vulnerable site to a malicious site. This is as if being redirected from eBay directly.
Covert Redirect is a class of security bugsdisclosed 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 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 was found and dubbed by a Mathematics PhD student Wang Jing from School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
After Covert Redirect was published, it is kept in some common databases such as SCIP, OSVDB, Bugtraq, and X-Force. Its scipID is 13185, while OSVDB reference number is 106567. Bugtraq ID: 67196. X-Force reference number is 93031.
Discover and Reporter: Wang Jing, Division of Mathematical Sciences (MAS), School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University (NTU), Singapore. (@justqdjing) http://tetraph.com/wangjing/
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 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)
(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
Google DoublClick.net has been used by spammers for long time. The following is a report in 2008.
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.” http://blog.mitechmate.com/remove-ad-doubleclick-net-redirect-virus/
Malwarebytes posted a news related to DoubleClick.net malvertising in 2014.
(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.
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
“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)
(3.2) eBay Covert Redirect Vulnerability Based on Googleads.g.doubleclick.net
“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)
(3.3) The New York Times (Nytimes.com) Covert Redirect Vulnerability Based on Google Doubleclick.net
“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)