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:
Wang Jing, 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
(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.