Report generated by XSS.Cx at Wed Aug 08 12:21:40 EDT 2012.

XSS, Reflected Cross Site Scripting, CWE-79, CAPEC-86, www.yellowpages.com

Contents

1. Cross-site scripting (reflected)

1.1. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [REST URL parameter 1]

1.2. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [REST URL parameter 2]

1.3. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [REST URL parameter 2]

1.4. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [name of an arbitrarily supplied request parameter]

1.5. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [name of an arbitrarily supplied request parameter]

2. Flash cross-domain policy

3. Cookie scoped to parent domain

4. Cross-domain script include

5. Cookie without HttpOnly flag set

6. Robots.txt file


1. Cross-site scripting (reflected)  next
There are 5 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 organization. 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 organization 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 organization 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://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [REST URL parameter 1]  next

Summary

Severity:   High
Confidence:   Firm
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The value of REST URL parameter 1 is copied into a JavaScript string which is encapsulated in single quotation marks. The payload b3503'%3bd8718ad505b was submitted in the REST URL parameter 1. This input was echoed as b3503';d8718ad505b in the application's response.

This behaviour demonstrates that it is possible to terminate the JavaScript string into which our data is being copied. 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.

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.

Request

Response

1.2. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [REST URL parameter 2]  previous  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The value of REST URL parameter 2 is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload f527c"><img%20src%3da%20onerror%3dalert(1)>95588451e2d was submitted in the REST URL parameter 2. This input was echoed as f527c"><img src=a onerror=alert(1)>95588451e2d 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 PoC attack demonstrated uses an event handler to introduce arbitrary JavaScript into the document.

Request

Response

1.3. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [REST URL parameter 2]  previous  next

Summary

Severity:   High
Confidence:   Firm
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The value of REST URL parameter 2 is copied into a JavaScript string which is encapsulated in single quotation marks. The payload ed36d'%3be9585c11548 was submitted in the REST URL parameter 2. This input was echoed as ed36d';e9585c11548 in the application's response.

This behaviour demonstrates that it is possible to terminate the JavaScript string into which our data is being copied. 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.

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.

Request

Response

1.4. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [name of an arbitrarily supplied request parameter]  previous  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The name of an arbitrarily supplied request parameter is copied into a JavaScript string which is encapsulated in double quotation marks. The payload f48a4</script><script>alert(1)</script>fac520b0cf0 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.

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.

Request

Response

1.5. http://www.yellowpages.com/newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then [name of an arbitrarily supplied request parameter]  previous

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The name of an arbitrarily supplied request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload 6db89'-alert(1)-'18c7cd72aca 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.

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.

Request

Response

2. Flash cross-domain policy  previous  next

Summary

Severity:   Low
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /crossdomain.xml

Issue detail

The application publishes a Flash cross-domain policy which uses a wildcard to specify allowed domains, allows access from specific other domains, and allows access from specific subdomains.

Using a wildcard to specify allowed domains means that any domain matching the wildcard expression can perform two-way interaction with this application. You should only use this policy if you fully trust every possible web site that may reside on a domain which matches the wildcard expression.

Allowing access from specific domains means that web sites on those domains can perform two-way interaction with this application. You should only use this policy if you fully trust the specific domains allowed by the policy.

Issue background

The Flash cross-domain policy controls whether Flash client components running on other domains can perform two-way interaction with the domain which publishes the policy. If another domain is allowed by the policy, then that domain can potentially attack users of the application. If a user is logged in to the application, and visits a domain allowed by the policy, then any malicious content running on that domain can potentially gain full access to the application within the security context of the logged in user.

Even if an allowed domain is not overtly malicious in itself, security vulnerabilities within that domain could potentially be leveraged by a third-party attacker to exploit the trust relationship and attack the application which allows access.

Issue remediation

You should review the domains which are allowed by the Flash cross-domain policy and determine whether it is appropriate for the application to fully trust both the intentions and security posture of those domains.

Request

Response

3. Cookie scoped to parent domain  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The following cookies were issued by the application and is scoped to a parent of the issuing domain:
  • vrid=1d48a400-6d87-012f-b517-00237da00940; domain=.yellowpages.com; path=/; expires=Fri, 21-Apr-2017 02:24:58 GMT
  • location=geo_term%3ANewton+Upper+Falls%2C+MA%7Clat%3A42.3139862%7Clng%3A-71.2194994%7Ccity%3ANewton+Upper+Falls%7Cstate%3AMA%7Cdisplay_geo%3ANewton+Upper+Falls%2C+MA; domain=.yellowpages.com; path=/; expires=Sun, 21-Apr-2013 02:24:59 GMT
  • b=10034; domain=.yellowpages.com; path=/; expires=Sat, 28-Apr-2012 02:24:59 GMT
The cookies do not appear to contain session tokens, which may reduce the risk associated with this issue. You should review the contents of the cookies to determine their function.

Issue background

A cookie's domain attribute determines which domains can access the cookie. Browsers will automatically submit the cookie in requests to in-scope domains, and those domains will also be able to access the cookie via JavaScript. If a cookie is scoped to a parent domain, then that cookie will be accessible by the parent domain and also by any other subdomains of the parent domain. If the cookie contains sensitive data (such as a session token) then this data may be accessible by less trusted or less secure applications residing at those domains, leading to a security compromise.

Issue remediation

By default, cookies are scoped to the issuing domain and all subdomains. If you remove the explicit domain attribute from your Set-cookie directive, then the cookie will have this default scope, which is safe and appropriate in most situations. If you particularly need a cookie to be accessible by a parent domain, then you should thoroughly review the security of the applications residing on that domain and its subdomains, and confirm that you are willing to trust the people and systems which support those applications.

Request

Response

4. Cross-domain script include  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The response dynamically includes the following scripts from other domains:
  • http://i1.ypcdn.com/webyp/javascripts/global_packaged.js?13937
  • http://i2.ypcdn.com/webyp/javascripts/preload_packaged.js?13937
  • http://i2.ypcdn.com/webyp/javascripts/search_packaged.js?13937
  • http://i2.ypcdn.com/webyp/javascripts/vendor/omniture_test_and_target/mbox.js?13937
  • http://www.bkrtx.com/js/bk-static.js
  • http://www.google.com/adsense/search/ads.js

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 fulfill, 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

Response

5. Cookie without HttpOnly flag set  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The following cookies were issued by the application and do not have the HttpOnly flag set:
  • vrid=1d48a400-6d87-012f-b517-00237da00940; domain=.yellowpages.com; path=/; expires=Fri, 21-Apr-2017 02:24:58 GMT
  • location=geo_term%3ANewton+Upper+Falls%2C+MA%7Clat%3A42.3139862%7Clng%3A-71.2194994%7Ccity%3ANewton+Upper+Falls%7Cstate%3AMA%7Cdisplay_geo%3ANewton+Upper+Falls%2C+MA; domain=.yellowpages.com; path=/; expires=Sun, 21-Apr-2013 02:24:59 GMT
  • search_terms=classic+tuxedo+toll+free+dial+1+then; path=/
  • parity_analytics=---+%0A%3Avisit_id%3A+zh3ut1rmwb9yvdtrha8z3cv6zewd6%0A%3Avisit_start_time%3A+2012-04-21+02%3A24%3A59.137111+%2B00%3A00%0A%3Alast_page_load%3A+2012-04-21+02%3A24%3A59.137113+%2B00%3A00%0A; path=/; expires=Tue, 21-Apr-2037 02:24:59 GMT
  • b=10034; domain=.yellowpages.com; path=/; expires=Sat, 28-Apr-2012 02:24:59 GMT
The cookies do not appear to contain session tokens, which may reduce the risk associated with this issue. You should review the contents of the cookies to determine their function.

Issue background

If the HttpOnly attribute is set on a cookie, then the cookie's value cannot be read or set by client-side JavaScript. This measure can prevent certain client-side attacks, such as cross-site scripting, from trivially capturing the cookie's value via an injected script.

Issue remediation

There is usually no good reason not to set the HttpOnly flag on all cookies. Unless you specifically require legitimate client-side scripts within your application to read or set a cookie's value, you should set the HttpOnly flag by including this attribute within the relevant Set-cookie directive.

You should be aware that the restrictions imposed by the HttpOnly flag can potentially be circumvented in some circumstances, and that numerous other serious attacks can be delivered by client-side script injection, aside from simple cookie stealing.

Request

Response

6. Robots.txt file  previous

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.yellowpages.com
Path:   /newton-upper-falls-ma/classic-tuxedo-toll-free-dial-1-then

Issue detail

The web server contains a robots.txt file.

Issue background

The file robots.txt is used to give instructions to web robots, such as search engine crawlers, about locations within the web site which robots are allowed, or not allowed, to crawl and index.

The presence of the robots.txt does not in itself present any kind of security vulnerability. However, it is often used to identify restricted or private areas of a site's contents. The information in the file may therefore help an attacker to map out the site's contents, especially if some of the locations identified are not linked from elsewhere in the site. If the application relies on robots.txt to protect access to these areas, and does not enforce proper access control over them, then this presents a serious vulnerability.

Issue remediation

The robots.txt file is not itself a security threat, and its correct use can represent good practice for non-security reasons. You should not assume that all web robots will honor the file's instructions. Rather, assume that attackers will pay close attention to any locations identified in the file. Do not rely on robots.txt to provide any kind of protection over unauthorized access.

Request

Response

Report generated by XSS.Cx at Wed Aug 08 12:21:40 EDT 2012.