Otra brecha de seguridad amenaza parte de Internet

Un nuevo fallo de seguridad amenaza Internet. En este caso se trata de Covert Redirect y ha sido descubierto por un estudiante chino en Singapur. Las empresas tienen en sus manos solucionar este problema.

encrypt

 

Cuando aún resuenan los ecos de Heartbleed y el terremoto que sacudió la red, nos acabamos de enterar que otra brecha de seguridad compromete Internet. En este caso se trata de un fallo que afecta a páginas como Google, Facebook, Microsoft, Linkedin, Yahoo, PayPal, GitHub o Mail.ru que usan estas herramientas de código abierto para autenticar a sus usuarios.

 

Este error permitiría a un atacante haga creer a un usuario que una nueva ventana que redirija a Facebook es segura cuando en realidad no lo es. Hasta aquí la técnica se parece al phishing pero lo que hace lo hace diferente es que Covert Redirect, que así se llama el nuevo exploit, usa el dominio real pero hace un bypass del servidor para conseguir la info. Lo mejor que podemos hacer cuando estemos navegando y pulsemos en un sitio que abre un pop up que nos pide logearnos en Facebook o Google es cerrar esa ventana para evitar que nos redirija a sitios sospechosos.

 

Wang Jing, estudiante de doctorado en la Universidad Técnica de Nanyang (Singapur), es quien ha descubierto la vulnerabilidad y le ha puesto nombre. El problema, según Jing, es que ni el proveedor ni la compañía quieren responsabilizarse de esta brecha ya que costaría mucho tiempo y dinero. Seguramente, ahora que se conoce el caso, las compañías se pondrán manos a la obra.

 

Artículos Relacionados:

Falha de segurança afetam logins de Facebook, Google e Microsoft

covert_redirect3

Um estudante de PHD de Singapura, Wang Jing, identificou a falha, chamada de “Covert Redirect”, que consegue usar domínios reais de sites para verificação de páginas de login falsas, enganando os internautas.

 

Os cibercriminosos podem criar links maliciosos para abrir janelas pop-up do Facebook pedindo que o tal aplicativo seja autorizado. Caso seja realizada esta sincronização, os dados pessoais dos usuários serão passados para os hackers.

 

Wang afirma que já entrou em contato com o Facebook, porém recebeu uma resposta de que “entende os riscos de estar associado ao OAuth 2.0″ e que corrigir a falha “é algo que não pode ser feito por enquanto”.

 

O Google afirmou que o problema está sendo rastreado, o LinkedIn publicou nota em que garante que já tomou medidas para evitar que a falha seja explorada, e a Microsoft negou que houvesse vulnerabilidade em suas páginas, apenas nas de terceiros.

 

A recomendação do descobridor da falha para os internautas é que evitem fazer o login com dados de confirmação de Facebook, Google ou qualquer outro serviço sem terem total certeza de que estão em um ambiente seguro.

 

 

Especialistas: erro é difícil de corrigir

O site CNET ouviu dois especialistas em segurança virtual sobre o assunto. Segundo Jeremiah Grossman, fundador e CEO interino da WhiteHat Security, afirma que a falha “não é fácil de corrigir”. Segundo Chris Wysopal, diretor da Veracode, a falha pode enganar muita gente.

 

“A confiança que os usuários dão ao Facebook e outros serviços que usam OAuth pode tornar mais fácil para os hackers enganarem as pessoas para que elas acabem dando suas informações pessoais a ele”, afirma Wsyopal.

 

 

 

notícias relacionadas:

하트블리드 이어 ‘오픈ID’와 ‘오쓰 (OAuth)’서도 심각한 보안 결함

covert_redirect_logo_tetraph


‘하트블리드(Heartbleed)’ 버그에 이어 가입자 인증 및 보안용 오픈소스 SW인 ‘오픈ID’와‘오쓰(OAuth)’에도 심각한 결함이 발견됐다고 씨넷, 벤처비트 등 매체들이 보도했다.

 

싱 가폴난양대학교에 재학중인 ‘왕 징(Wang Jing)’ 박사는 수 많은 웹사이트와 구글, 페이스북, 링크드인, MS, 페이팔 등에서 사용하고 있는 로그인 툴인 ‘OAuth’와‘오픈ID’에 치명적인 결함이 발견됐다고 밝혔다. ‘코버트리디렉트(Covert Redirect)’라고 일컬어지는 이 결함은 감염된 도메인의 로그인 팝업을 통해 해킹이 이뤄진다.

 

가 령 인터넷 사용자들이 악의적인 피싱 사이트를 클릭하면 가입자 인증을 위해 페이스북 팝업 윈도가 뜨는데 가입자를 속이 기위해 가짜 도메인 이름을 사용하는 것이 아니라 진짜 사이트의 도메인을 활용한다고 한다. 만일 가입자가 로그인을 하면 합법적인 사이트가 아니라 피싱사이트로 e메일 주소, 생일, 연락처 등 개인 정보들이 흘러들어간다.

 

왕 은 페이스북 등 업체에 이 같은 결함을 알렸으며 페이스북은 결함이 OAuth 2.0가 연관된 것으로 인식하고 있지만 짧은 시간내 해결될 수는 없을 것이란 답을 얻은 것으로 알려졌다. 왕은 이번 결함이 구글, 링크드인, 마이크로소프트, 페이스북, 페이팔 등 다수의 오픈ID와 OAuth를 활용하는 기업들이 영향을 받을 것으로 예상했다.

 

왕 은 “제3의 애플리케이션 개발자들이 화이트리스트를 엄격하게 적용하면 해커 공격의 빌미를 제공하지 않을 것”이라고 말했다. 하지만 “실제로 많은 애플리케이션 개발자들이 여러가지 이유로 이런 조치를 취하지않고 있다는 게 OAuth 2.0과 오픈ID의 결함 문제를 심각하게 만들고 있다”고 덧붙였다.

 

 



 

OAuthとOpenIDに深刻な脆弱性か–Facebookなど大手サイトに影響も

digital-security-padlock-protection-binary-virus-hack-malware

 

OpenSSLの脆弱性「Heartbleed」に続き、人気のオープンソースセキュリ ティソフトウェアでまた1つ大きな脆弱性が見つかった。今回、脆 弱性が見つかったのはログインツールの「OAuth」と「OpenID」で、これらのツールは多数のウェブサイトと、Google、Facebook、 Microsoft、LinkedInといったテクノロジ大手に使われている。

 

シンガポールにあるNanyang Technological University(南洋理工大学)で学ぶ博士課程の学生Wang Jing氏は、「Covert Redirect」という深刻な脆弱性によって、影響を受けるサイトのドメイン上でログイン用ポップアップ画面を偽装できることを発見した。Covert Redirectは、既知のエクスプロイトパラメータに基づいている。

 

たとえば、悪意あるフィッシングリンクをクリックすると、 Facebook内でポップアップウィンドウが開き、アプリを許可するよう求められる。 Covert Redirect脆弱性の場合、本物に似た偽ドメイン名を使ってユーザーをだますのではなく、本物のサイトアドレスを使って許可を求める。

 

ユーザーがログインの許可を選択すると、正当なウェブサイトではなく攻撃者に個人データが送られてしまう。渡される個人データは、何を要求されるかにもよるが、メールアドレス、誕生日、連絡先リスト、さらにはアカウント管理情報にも及ぶ可能性がある。

 

アプリを許可したかどうかにかかわらず、標的になったユーザーはその後、攻撃者が選ぶウェブサイトにリダイレクトされ、そこでさらなる攻撃を受ける可能性がある。

 

Wang 氏によると、すでにFacebookには連絡し、この脆弱性を報告したが、同社は「OAuth 2.0に関連するリスクは理解していた」と述べた上で、「当プラットフォーム上の各アプリケーションにホワイトリストの利用を強制することが難しい」た め、このバグを修正することは「短期間で達成できるものではない」と返答したという。

 

影響を受けるサイトはFacebookだけではない。Wang氏は、Google、LinkedIn、Microsoftにもこの件を報告したが、問題への対処についてさまざまな回答を受け取ったと述べている。

 

Google(OpenID を利用している)はWang氏に、現在この問題に取り組んでいると伝えた。LinkedInは、この件に関するブログを公開 したと述べた。一方でMicrosoftは、調査を行ったところ、脆弱性はサードパーティーのドメインに存在しており、自社サイトには存在しないと述べ た。

 

この記事は海外CBS Interactive発の記事を朝日インタラクティブが日本向けに編集したものです。



 

 

 

関連ニュース:
http://www.cnet.com/news/serious-security-flaw-in-oauth-and-openid-discovered/

Sicherheitslücke in OAuth 2.0 und OpenID gefunden

covert_redirect3

Wang Jing, Student an der Nanyang Technological University in Singapur, hat nach dem Bekanntwerden des OpenSSL-Heartbleed-Lecks, eine weitere schwere Sicherheitslücke entdeckt, diesmal in den Authentifizierungsmethoden OAuth 2.0 und OpenID. Die als “Covert Redirect” (“Heimliche Umleitung”) benannte Sicherheitslücke ermöglicht es Angreifern, dem Nutzer einen echt aussehenden Login-Screen unterzujubeln und sich so Zugriff auf die bereitgestellten Daten zu verschaffen. Das gefährliche daran: Die Sicherheitslücke besitzt – anders als bisher bekannte Fishing-Versuche – eine legitime Domainadresse, kann also über einen Blick in die URL-Zeile des Browsers nicht oder nur sehr schwer entlarvt werden. Auf OAuth 2.0 und OpenID bieten inzwischen zahlreiche Webdienste um einen direkten Login in andere Dienste und Apps zu ermöglichen, darunter auch Google, Facebook, Microsoft und Co.

 

So ist es möglich, dem Nutzer eine Mail mit einem speziell präparierten Link zukommen zu lassen, ein Klick auf diesen öffnet eben wie gesagt eine legitime Adresse samt entsprechendem Logo. Autorisiert der Nutzer dann diese Anfrage und loggt sich in den Dienst ein, so werden die Daten nicht an die vermeintliche App weitergeleitet, sondern gelangen eben in den Besitz des Angreifers. Je nachdem, welche Daten abfragt werden, bekommt dieser somit also E-Mail-Adresse, Geburtsdatum, Kontaktlisten und dergleichen. Ebenso ist es möglich, den Nutzer nach dem Login auf eine beliebige Webseite, welche unter Umständen Malware verbreitet, weiterzuleiten.



covert-redirect-11

 

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Die Lösung des Problems könnte aber – wenn es überhaupt einmal eine geben sollte – eine langwierige Sache sein. Wang Jing hat bereits etliche größere Anbieter der Loginmethoden angeschrieben und über die gefundene Sicherheitslücke aufgeklärt, hierbei gab es jedoch unterschiedliche Aussagen. Im Hause Google beobachtet man das Problem, Microsoft ist sich keiner Schuld bewusst und schiebt die Sicherheitslücke an Drittanbieter ab. Lediglich Facebook scheint hier ehrlich zu sein und gibt an, dass es sich dabei um ein grundsätzliches Problem von OAuth 2.0 und OpenID handelt – möchte man nicht eine umfangreiche Whitelist mit sämtlichen nicht-schädlichen Apps pflegen, ist die Sicherheitslücke nicht “mal eben so” zu beheben. Im Grunde dürften sich sämtliche Gegenmaßnahmen negativ auf die Nutzererfahrung auswirken, was natürlich keiner der Dienste in Kauf nehmen möchte – und so bleibt es hierbei scheinbar beim “kleineren Übel” für die Anbieter.

So bleibt eigentlich nur die Möglichkeit, auf OAuth 2.0 oder OpenID als Login-Methode für Drittanbieter Dienste und Apps zu verzichten oder genauestens darauf zu achten, auf was man klickt. Hat man keine explizite Autorisierung angestoßen, sollte man die geöffneten Tabs umgehend schließen und darauf hoffen, dass sich nicht doch irgendwo ein falscher Link eingepfercht hat.



Quelle:
http://www.blogtogo.de/sicherheitsluecke-in-oauth-2-0-und-openid-gefunden/




Sina Weibo OAuth 2.0 Service Covert Redirect Web Security Bugs (Information Leakage & Open Redirect)

china

Sina Weibo OAuth 2.0 Service Covert Redirect Web Security Bugs (Information Leakage & Open Redirect)

 

 

(1) Domain:
weibo.com

“Sina Weibo (NASDAQ: WB) is a Chinese microblogging (weibo) website. Akin to a hybrid of Twitter and Facebook, it is one of the most popular sites in China, in use by well over 30% of Internet users, with a market penetration similar to the United States’ Twitter. It was launched by SINA Corporation on 14 August 2009, and has 503 million registered users as of December 2012. About 100 million messages are posted each day on Sina Weibo. In March 2014, Sina Corporation announced a spinoff of Weibo as a separate entity and filed an IPO under the symbol WB. Sina retains 56.9% ownership in Weibo. The company began trading publicly on April 17, 2014. “Weibo” (微博) is the Chinese word for “microblog”. Sina Weibo launched its new domain name weibo.com on 7 April 2011, deactivating and redirecting from the old domain, t.sina.com.cn to the new one. Due to its popularity, the media sometimes directly uses “Weibo” to refer to Sina Weibo. However, there are other Chinese microblogging/weibo services including Tencent Weibo, Sohu Weibo and NetEase Weibo.” (Wikipedia)

(2) Vulnerability Description:

Weibo 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:

Weibo’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 Weibo.

 

At the same time, it can be used to collect sensitive information of both third-party app and users by using the following parameters (sensitive information is contained in HTTP header.),

“&response_type”=sensitive_info,token…

“&scope”=get_user_info%2Cadd_share…

 

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

 

The vulnerabilities occurs at page “oauth2/authorize?” with parameter “&redirect_uri”, e.g.
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2Findex.php%3Fm%3DUser%26a%3Dcallback%26type%3Dsina&response_type=code [1]

 

Before acceptance of third-party application:

When a logged-in Weibo 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 Weibo and clicks the URL ([1]) above, the same situation will happen upon login.

 

After acceptance of third-party application:

A logged-in Weibo 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) Weibo 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 Weibo 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 Weibo directly. The number of Weibo’s OAuth 2.0 client websites is so huge that such Attacks could be commonplace.

 

Before acceptance of the third-party application, Weibo’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 Weibo’s authentication system and attack more easily.

 

Used one of webpages for the following tests. The webpage is “https://biyiniao.wordpress.com/“. We 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

 

Vulnerable URL in this domain:
http://uc.cjcp.com.cn/?m=user&a=otherLogin&type=sina&furl=http%3A%2F%2Ftetraph.com%2Fessayjeans%2Fseasons%2F%25E7%25A5%25AD%25E6%2598%25A5.html

 

Vulnerable URL from Weibo that is related to cjcp.com.cn:
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2Findex.php%3Fm%3DUser%26a%3Dcallback%26type%3Dsina&response_type=code

 

POC:
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2F%3Fm%3Duser%26a%3DotherLogin%26type%3Dsina%26furl%3Dhttp%253A%252F%252Ftetraph.com%252Fessayjeans%252Fseasons%252F%2525E7%2525A5%2525AD%2525E6%252598%2525A5.html&response_type=code [2]

 

(2.2) Another method for attackers.


Attackers enter the following URL in browser,
http://uc.cjcp.com.cn/?m=user&a=otherLogin&type=sina&furl=http%3A%2F%2Ftetraph.com%2Fessayjeans%2Fseasons%2F%25E7%25A5%25AD%25E6%2598%25A5.html

 

Then, attackers can get URL below,
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2Findex.php%3Fm%3DUser%26a%3Dcallback%26type%3Dsina&response_type=code [3]

 

If users click URL [3], the same thing will happen as URL [2].

 

 

 

POC Video:
https://www.youtube.com/watch?v=eKozHxrk4js

 

Blog Detail:
http://tetraph.blogspot.com/2014/05/sina-weibo-oauth-20-covert-redirect.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, such as 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)
http://tetraph.com/wangjing/

 

Related Articles:
http://diebiyi.com/articles/security/covert-redirect/sinas-oauth-2-0-covert-redirect-vulnerability-information-leakage-open-redirect/
http://tetraph.com/security/covert-redirect/sina-weibo-oauth-2-0-covert-redirect-vulnerability-information-leakage-open-redirect/
https://redysnowfox.wordpress.com/2014/08/02/sina-exploit/
http://qianqiuxue.tumblr.com/post/118901060925/itinfotech-covert#notes
http://webtechhut.blogspot.com/2014/07/sina-bug.html
https://twitter.com/yangziyou/status/614745661704015873
http://tetraph.blog.163.com/blog/static/2346030512014463356551/
http://biboying.lofter.com/post/1cc9f4f5_706b6c3
http://frenchairing.blogspot.fr/2014/07/sina-hacking.html
http://www.inzeed.com/kaleidoscope/covert-redirect/sina-weibo-oauth-2-0-covert-redirect-vulnerability-information-leakage-open-redirect/
https://biyiniao.wordpress.com/2014/06/07/sina-research/

==========

 

新浪 微博 网站 OAuth 2.0 隐蔽重定向 (Covert Redirect) 网络安全漏洞 (信息泄漏 & 公开重定向)





(1) 域名:
weibo.com

” 新浪微博是一个由新浪网推出,提供微型博客服务类的社交网站。用户可以通过网页、WAP页面、手机客户端、手机短信、彩信发布消息或上传图片。新浪可以把 微博理解为“微型博客”或者“一句话博客”。用户可以将看到的、听到的、想到的事情写成一句话,或发一张图片,通过电脑或者手机随时随地分享给朋友,一起 分享、讨论;还可以关注朋友,即时看到朋友们发布的信息” (百度百科)

 

 

(2) 漏洞描述:

新浪 微博 网站有有一个计算机安全问题,黑客可以对它进行隐蔽重定向 (Covert Redirect) 网络攻击。

 

 

这 个漏洞不需要用户登录,测试是基于微软 Windows 8 的 IE (10.0.9200.16750); Ubuntu (14.04) 的 Mozilla 火狐 (Firefox 34.0) 和 谷歌 Chromium 39.0.2171.65-0; 以及苹果 OS X Lion 10.7 的 Safari 6.16。


(2.1) 漏洞细节:
Weibo 的 OAuth 2.0 系统可能遭到攻击。更确切地说, Weibo 对 OAuth 2.0 系统的 parameter “&redirect_uri“ 验证不够充分。可以用来构造对 Weibo 的 URL跳转 攻击。

与此同时,这个漏洞可以用下面的参数来收集第三方 App 和 用户 的敏感信息(敏感信息包含在 HTTP header里),

“&response_type”=sensitive_info,token,code…

“&scope”=get_user_info%2Cadd_share…

 

它也增加了对第三方网站 URL跳转 攻击的成功率。

 

漏洞地点 “oauth2/authorize?”,参数”&redirect_uri”, e.g.
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2Findex.php%3Fm%3DUser%26a%3Dcallback%26type%3Dsina&response_type=code [1]

 

同意三方 App 前:

当一个已经登录的 Weibo 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 “&redirect_uri” 的 URL。


如果没有登录的 Weibo 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 Weibo 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 Weibo 用户没有登录,攻击依然可以在要求他登录的Weibo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) Weibo 一般会允许属于已被验证过得三方 App domain 的所有 URLs。 然而,这些 URLs 可以被操控。比如,参数 “&redirect_uri” 是被三方 App 设置的,但攻击者可以修改此参数的值。

 

因此,Weibo 用户意识不到他会被先从 Weibo 跳转到第三方 App 的网页,然后从此网页跳转到有害的网页。这与从 Weibo 直接跳转到有害网页是一样的。

 

因为 Weibo 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,Weibo 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 Weibo 的 URL跳转 验证系统。

 

用了一个页面进行了测试, 页面是 “http://tetraphlike.lofter.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=user&a=otherLogin&type=Weibo&furl=http%3A%2F%2Ftetraph.com%2Fessayjeans%2Fseasons%2F%25E7%25A2%258E%25E5%25A4%258F.html

 

Weibo 与 cjcp.com.cn 有关的有漏洞的 URL:
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2Findex.php%3Fm%3DUser%26a%3Dcallback%26type%3Dsina&response_type=code

 

POC:
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2F%3Fm%3Duser%26a%3DotherLogin%26type%3Dsina%26furl%3Dhttp%253A%252F%252Ftetraph.com%252Fessayjeans%252Fseasons%252F%2525E7%2525A5%2525AD%2525E6%252598%2525A5.html&response_type=code [2]

 



(2.2) 攻击的另一个方法.


攻击者在浏览器输入 URL,
http://uc.cjcp.com.cn/?m=user&a=otherLogin&type=sina&furl=http%3A%2F%2Ftetraph.com%2Fessayjeans%2Fseasons%2F%25E7%25A5%25AD%25E6%2598%25A5.html

 

然后,攻击者可以得到 URL,
https://api.weibo.com/oauth2/authorize?client_id=2021435350&redirect_uri=http%3A%2F%2Fuc.cjcp.com.cn%2Findex.php%3Fm%3DUser%26a%3Dcallback%26type%3Dsina&response_type=code [3]

 

如果用户点击 URL [3], 发生的事情和 URL [2] 一样.

 




(2.3)下面的 URLs 有同样的漏洞.
https://api.t.sina.com.cn/oauth2/authorize?client_id=496934491&redirect_uri=http%3A%2F%2Fwww.paidai.com%2Fsiteuser%2Foauth_sina.php%3Ffrom%3Dweibo&response_type=code

 

POC 视频:
https://www.youtube.com/watch?v=eKozHxrk4js

 

博客细节:
http://tetraph.blogspot.com/2014/05/sina-weibo-oauth-20-covert-redirect.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。

 

 

 

 



Serious security flaw in OAuth, OpenID discovered

Following in the steps of the OpenSSL vulnerability Heartbleed, A serious Covert Redirect vulnerability related to OAuth 2.0 and OpenID has been found. Almost all major providers of OAuth 2.0 and OpenID are affected, such as Facebook, Google, Yahoo, LinkedIn, Microsoft, Paypal, GitHub, QQ, Taobao, Weibo, VK, Mail.Ru, Sohu, etc.

 

Wang Jing, a Ph.D. student at the Nanyang Technological University in Singapore, discovered that the serious vulnerability “Covert Redirect” flaw can masquerade as a log-in popup based on an affected site’s domain. Covert Redirect is based on a well-known exploit parameter.

 

For example, someone clicking on a malicious phishing link will get a popup window in Facebook, asking them to authorize the app. Instead of using a fake domain name that’s similar to trick users, the Covert Redirect flaw uses the real site address for authentication.

 

If a user chooses to authorize the log in, personal data (depending on what is being asked for) will be released to the attacker instead of to the legitimate website. This can range from email addresses, birth dates, contact lists, and possibly even control of the account.

 

Regardless of whether the victim chooses to authorize the app, he or she will then get redirected to a website of the attacker’s choice, which could potentially further compromise the victim.

 

Wang says he has already contacted Facebook and has reported the flaw, but was told that the company “understood the risks associated with OAuth 2.0,” and that “short of forcing every single application on the platform to use a whitelist,” fixing this bug was “something that can’t be accomplished in the short term.”

 

Facebook isn’t the only site affected. Wang says he has reported this to Google, LinkedIn, and Microsoft, which gave him various responses on how they would handle the matter.

 

covert_redirect_logo_tetraph


Google (which uses OpenID) told him that the problem was being tracked, while LinkedIn said that the company has published a blog on the matter. Microsoft, on the other hand, said an investigation had been done and that the vulnerability existed on the domain of a third party and not on its own sites.

“Patching this vulnerability is easier said than done. If all the third-party applications strictly adhere to using a whitelist, then there would be no room for attacks,” said Wang.

 

“However, in the real world, a large number of third-party applications do not do this due to various reasons. This makes the systems based on OAuth 2.0 or OpenID highly vulnerable,” he added.

 

LinkedIn engineer Shikha Sehgal wrote a blog post about the creation of a whitelist for the site more than a month before Wang published his findings.

 

“In order to make the LinkedIn platform even more secure, and so we can comply with the security specifications of OAuth 2, we are asking those of you who use OAuth 2 to register your application’s redirect URLs with us by April 11, 2014,” she said.

 

Sehgal did not explicitly say that the measure was in response to a flaw in OAuth 2, but the social network did confirm to CNET that the vulnerability that Wang detailed is the same one that inspired the blog post.

 

PayPal also has addressed the flaw.

“When PayPal implemented OAuth2.0/OpenID, we engineered additional security measures to protect our merchants and customers. These measures protect PayPal customers from this specific OAuth2.0/OpenID vulnerability,” James Barrese, PayPal’s CTO, said in a blog post on Friday. PayPal declined to add details about those measures.

(Article Mainly from Cnet.com)

 

 

 

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