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 defenses:
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.
The value of the keys request parameter is copied into the HTML document as plain text between tags. The payload 1f82f<script>alert(1)</script>d55a495333 was submitted in the keys 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.
The value of the username request parameter is copied into the HTML document as plain text between tags. The payload 1bcd4<script>alert(1)</script>d253e6aeae3 was submitted in the username 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.
The cookie appears to contain a session token, which may increase the risk associated with this issue. You should review the contents of the cookie to determine its function.
Issue background
If the secure flag is set on a cookie, then browsers will not submit the cookie in any requests that use an unencrypted HTTP connection, thereby preventing the cookie from being trivially intercepted by an attacker monitoring network traffic. If the secure flag is not set, then the cookie will be transmitted in clear-text if the user visits any HTTP URLs within the cookie's scope. An attacker may be able to induce this event by feeding a user suitable links, either directly or via another web site. Even if the domain which issued the cookie does not host any content that is accessed over HTTP, an attacker may be able to use links of the form http://example.com:443/ to perform the same attack.
Issue remediation
The secure flag should be set on all cookies that are used for transmitting sensitive data when accessing content over HTTPS. If cookies are used to transmit session tokens, then areas of the application that are accessed over HTTPS should employ their own session handling mechanism, and the session tokens used should never be transmitted over unencrypted communications.
The application appears to disclose some server-side source code written in ASP.
Issue background
Server-side source code may contain sensitive information which can help an attacker formulate attacks against the application.
Issue remediation
Server-side source code is normally disclosed to clients as a result of typographical errors in scripts or because of misconfiguration, such as failing to grant executable permissions to a script or directory. You should review the cause of the code disclosure and prevent it from happening.
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).
The following email address was disclosed in the response:
bdillard@pathf.com
Request
GET /includes/blank.html HTTP/1.1 Host: jira.jboss.org Accept: */* Accept-Language: en User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0) Connection: close Cookie: JSESSIONID=054235C303669934768F68853A63ADCC;
Response
HTTP/1.1 200 OK Date: Mon, 15 Nov 2010 14:00:45 GMT Server: Apache-Coyote/1.1 X-AREQUESTID: 540x976460x12 X-ASESSIONID: 3jsbox X-AUSERNAME: anonymous Accept-Ranges: bytes ETag: W/"1794-1289305038000" Last-Modified: Tue, 09 Nov 2010 12:17:18 GMT Content-Type: text/html;charset=UTF-8 Content-Length: 1794 Vary: Accept-Encoding Connection: close
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!-- Copyright (c) 2007 Brian Dillard and Brad Neuberg: Brian Dillard | Project Lead | bdillard@pathf.com | http://blogs.pathf.com/agileajax/ Brad Neuberg | Original Project Creator | http://codinginparadise.org
Permission is hereby granted, free of charge, to any person obtaining a copy of this software ...[SNIP]...
The following email addresses were disclosed in the response:
akazakov@exadel.com
baunax@gmail.com
bbrowning@redhat.com
dave.siracusa@perfware.com
ishaikovsky@exadel.com
lzoubek@redhat.com
mareshkau@exadel.com
mgencur@redhat.com
mposolda@redhat.com
mputz@jboss.com
nbelaevski@exadel.com
toni@rikkola.net
Request
GET /plugins/servlet/streams HTTP/1.1 Host: jira.jboss.org Accept: */* Accept-Language: en User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0) Connection: close Cookie: JSESSIONID=054235C303669934768F68853A63ADCC;
Response
HTTP/1.1 200 OK Date: Mon, 15 Nov 2010 14:00:44 GMT Server: Apache-Coyote/1.1 X-AREQUESTID: 540x976458x11 X-ASESSIONID: 3jsbox X-AUSERNAME: anonymous Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Expires: Wed, 31 Dec 1969 23:59:59 GMT Content-Type: application/xml;charset=UTF-8 Vary: Accept-Encoding Connection: close Content-Length: 29389
Unless directed otherwise, browsers may store a local cached copy of content received from web servers. Some browsers, including Internet Explorer, cache content accessed via HTTPS. If sensitive information in application responses is stored in the local cache, then this may be retrieved by other users who have access to the same computer at a future time.
Issue remediation
The application should return caching directives instructing browsers not to store local copies of any sensitive data. Often, this can be achieved by configuring the web server to prevent caching for relevant paths within the web root. Alternatively, most web development platforms allow you to control the server's caching directives from within individual scripts. Ideally, the web server should return the following HTTP headers in all responses containing sensitive content:
GET /includes/blank.html HTTP/1.1 Host: jira.jboss.org Accept: */* Accept-Language: en User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0) Connection: close Cookie: JSESSIONID=054235C303669934768F68853A63ADCC;
Response
HTTP/1.1 200 OK Date: Mon, 15 Nov 2010 14:00:45 GMT Server: Apache-Coyote/1.1 X-AREQUESTID: 540x976460x12 X-ASESSIONID: 3jsbox X-AUSERNAME: anonymous Accept-Ranges: bytes ETag: W/"1794-1289305038000" Last-Modified: Tue, 09 Nov 2010 12:17:18 GMT Content-Type: text/html;charset=UTF-8 Content-Length: 1794 Vary: Accept-Encoding Connection: close
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!-- Copyright (c) 2007 Brian Dillard and Brad Neuberg: Brian Dillard | Proje ...[SNIP]...
The response contains the following Content-type statement:
Content-Type: text/html;charset=UTF-8
The response states that it contains HTML. However, it actually appears to contain plain text.
Issue background
If a web response specifies an incorrect content type, then browsers may process the response in unexpected ways. If the specified content type is a renderable text-based format, then the browser will usually attempt to parse and render the response in that format. If the specified type is an image format, then the browser will usually detect the anomaly and will analyse the actual content and attempt to determine its MIME type. Either case can lead to unexpected results, and if the content contains any user-controllable data may lead to cross-site scripting or other client-side vulnerabilities.
In most cases, the presence of an incorrect content type statement does not constitute a security flaw, particularly if the response contains static content. You should review the contents of the response and the context in which it appears to determine whether any vulnerability exists.
Issue remediation
For every response containing a message body, the application should include a single Content-type header which correctly and unambiguously states the MIME type of the content in the response body.
Request
GET /plugins/servlet/gadgets/ifr HTTP/1.1 Host: jira.jboss.org Accept: */* Accept-Language: en User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0) Connection: close Cookie: JSESSIONID=054235C303669934768F68853A63ADCC;
Response
HTTP/1.1 200 OK Date: Mon, 15 Nov 2010 14:00:43 GMT Server: Apache-Coyote/1.1 X-AREQUESTID: 540x976429x5 X-ASESSIONID: 3jsbox X-AUSERNAME: anonymous Content-Type: text/html;charset=UTF-8 Content-Length: 34 Vary: Accept-Encoding Connection: close
Missing or malformed url parameter
Report generated by XSS.CX at Mon Nov 15 08:03:39 CST 2010.