Alibaba Alipay Online Website OAuth 2.0 Covert Redirect Web Security Bugs (Information Leakage & Open Redirect)
(1) Domain:
alipay.com
"Alipay.com is a third-party online payment platform with no transaction fees. It was launched in China in 2004 by Alibaba Group and its founder Jack Ma. According to analyst research report, Alipay has the biggest market share in China with 300 million users and control of just under half of China's online payment market in February 2014. According to Credit Suisse, the total value of online transactions in China grew from an insignificant size in 2008 to around RMB 4 trillion (US$660 billion) in 2012. Alipay provides an escrow service, in which consumers can verify whether they are happy with goods they have bought before releasing money to the seller. This service was offered for what the company says are China's weak consumer protection laws, which have reduced consumer confidence in C2C and even B2C quality control." (Wikipedia)
(2) Vulnerability Description:
Alipay 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:
Alipay's OAuth 2.0 system is susceptible to Attacks. More specifically, the authentication of parameter "&goto" in OAuth 2.0 system is insufficient. It can be misused to design Open Redirect Attacks to Alipay.
At the same time, it can be used to collect sensitive information of both third-party app and users (sensitive information is contained in HTTP header.).
It increases the likelihood of successful Open Redirect Attacks to third-party websites, too.
The vulnerabilities occurs at page "/express.htm?" with parameter "&goto", e.g.
Before acceptance of third-party application:
When a logged-in Alipay 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 "&goto".
If a user has not logged onto Alipay and clicks the URL ([1]) above, the same situation will happen upon login.
After acceptance of third-party application:
A logged-in Alipay 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) Before acceptance of the third-party application, Alipay'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 Alipay's authentication system and attack more easily.
Used one of webpages for the following tests. The webpage is "http://lifegreen.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:
cjcp.com.cn
Attackers enter the following URL in browser,
Then, attackers can get URL below,
If users click URL [2], attacks happen.
POC Video:
https://www.youtube.com/watch?v=lhqwC9RQl44
Blog Detail:
http://tetraph.blogspot.com/2014/05/alibaba-alipays-oauth-20-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. 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)
Related Articles:
http://tetraph.com/security/covert-redirect/alibaba-alipays-oauth-2-0-covert-redirect-vulnerability-information-leakage-open-redirect/
http://securityrelated.blogspot.com/2014/07/alibaba-alipay-bug.html
http://whitehatpost.lofter.com/post/1cc773c8_72e71f9
https://vulnerabilitypost.wordpress.com/2014/06/02/alibaba-alipay-exploit/
https://twitter.com/yangziyou/status/614368472705818624
blog.163.com/tetraph/blog/static/2346030512014471384217
http://whitehatview.tumblr.com/post/119488487851/securitypost-itinfotech-falha-de-seguranca#notes
http://computerobsess.blogspot.com/2014/07/alibaba-alipay-bug.html
Alipay 的 OAuth 2.0 系统可能遭到攻击。更确切地说， Alipay 对 OAuth 2.0 系统的 parameter “&goto“ 验证不够充分。可以用来构造对 Alipay 的 URL跳转 攻击。
与此同时，这个漏洞可以用来收集第三方 App 和 用户 的敏感信息（敏感信息包含在 HTTP header里），
它也增加了对第三方网站 URL跳转 攻击的成功率。
漏洞地点 "login/express.htm?"，参数"&goto", e.g.
https://auth.alipay.com/login/express.htm?goto=https%3A%2F%2Fmemberexprod.alipay.com%2Fauthorize%2FuserAuthQuickLoginAction.htm%3Fe_i_i_d%3D41da904223e68d291bfb0eecbff264e1 [1]
同意三方 App 前：
当一个已经登录的 Alipay 用户点击上面的 URL ([1]), 对话框会询问他是否接受第三方 App 接收他的信息。如果同意，他会被跳转到 参数 "&goto" 的 URL。
如果没有登录的Alipay 用户点击 URL ([1]), 他登录后会发生同样的事情。
同意三方 App 后：
已经登录的 Alipay 用户 不会再被询问是否接受 三方 App。当他点击 URL ([1]) 时，他会被直接跳转到攻击者控制的页面。
如果 Alipay 用户没有登录，攻击依然可以在要求他登录的Alipay的对话框被确认后完成（这个过程不会提示任何和三方 App 有关的内容）
。
(2.1.1) 因为 Alipay 的 OAuth 2.0 客户很多，这样的攻击可以很常见。
在同意三方 App 之前，Alipay 的 OAuth 2.0 让用户更容易相信被跳转的页面是安全的。这增加了三方 App 被 URL跳转 攻击的成功率。
同意三方 App 后， 攻击者可以完全绕过 Alipay 的 URL跳转 验证系统。
用了一个页面进行了测试， 页面是 "http://canghaixiao.tumblr.com/". 可以假定它是有害的，并且含有收集三方 App 和用户敏感信息的 code。
下面是一个有漏洞的三方 domain:
cjcp.com.cn
这个 domain 有漏洞的 URL:
http://uc.cjcp.com.cn/?m=pay&a=login&furl=http%3A%2F%2Ftetraph.com%2Fessayjeans%2Foutings%2F%25E5%2590%25AC%25E6%25B5%25B7.html
攻击者在浏览器输入 URL,
http://uc.cjcp.com.cn/?m=pay&a=login&furl=http%3A%2F%2Ftetraph.com%2Fessayjeans%2Foutings%2F%25E5%2590%25AC%25E6%25B5%25B7.html
然后，攻击者可以得到 URL,
https://auth.alipay.com/login/express.htm?goto=https%3A%2F%2Fmemberexprod.alipay.com%2Fauthorize%2FuserAuthQuickLoginAction.htm%3Fe_i_i_d%3D41da904223e68d291bfb0eecbff264e1 [2]
如果用户点击 URL [2], 攻击发生。
POC 视频:
https://www.youtube.com/watch?v=lhqwC9RQl44
博客细节:
http://tetraph.blogspot.com/2014/05/alibaba-alipays-oauth-20-covert.html
(3) 什么是隐蔽重定向?
隐蔽重定向 (Covert Redirect) 是一个计算机网络安全漏洞。这个漏洞发布于 2014年5月。漏洞成因是网络应用软件对跳转到合作者的跳转没有充分过滤。这个漏洞经常利用第三方网站 (包括合作网站) 的公开重定向 (Open Redirect) 或者 跨站脚本漏洞 (XSS - Cross-site Scripting) 问题。
隐蔽重定向也对单点登录 (single sign-on) 有影响。最初发布的是对两款常用登录软件 OAuth 2.0 和 OpenID 的影响。黑客可以利用真实的网站进行网络钓鱼，从而窃取用户敏感信息。几乎所用提供 OAuth 2.0 和 OpenID 服务的网站都被影响。隐蔽重定向还可以和 跨站请求伪造 (CSRF - Cross-site Request Forgery) 一起利用。它的 scipID ID 是 13185; OSVDB ID 是 106567; Bugtraq ID 是 67196; X-Force ID 是 93031。
http://tetraph.com/security/covert-redirect/alibaba-alipays-oauth-2-0-covert-redirect-vulnerability-information-leakage-open-redirect/
http://securityrelated.blogspot.com/2014/07/alibaba-alipay-bug.html
http://whitehatpost.lofter.com/post/1cc773c8_72e71f9
https://vulnerabilitypost.wordpress.com/2014/06/02/alibaba-alipay-exploit/
https://twitter.com/yangziyou/status/614368472705818624
blog.163.com/tetraph/blog/static/2346030512014471384217
http://whitehatview.tumblr.com/post/119488487851/securitypost-itinfotech-falha-de-seguranca#notes
http://computerobsess.blogspot.com/2014/07/alibaba-alipay-bug.html
