-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Wordpress Security audit BulletProof Security 1. Cross-site scripting (reflected) Summary Severity: High Confidence: Certain Host: http://127.0.0.1 Path: /wp-admin/admin.php?page=bulletproof-security/admin/options.php Issue detail The value of the Accept-Encoding HTTP header is copied into the HTML document as plain text between tags. The payload a7123<script>alert(1)</script>78089b4648b was submitted in the Accept-Encoding HTTP header. 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. 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 (&lt; &gt; 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. Request GET /wp-admin/admin.php?page=bulletproof-security/admin/options.php HTTP/1.1 Host: 127.0.0.1 User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:11.0) Gecko/20100101 Firefox/11.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip, deflatea7123<script>alert(1)</script>78089b4648b Proxy-Connection: keep-alive Referer: http://127.0.0.1/wp-admin/options-general.php?page=custom-field-template.php Cookie: wordpress_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C0bc36ed70eff4d014b8f8f399e7931d9; bb2_screener_=1334010184+127.0.0.1; PHPSESSID=r0pobhl4p21uu57ek6lpdabr76; wordpress_test_cookie=WP+Cookie+check; wp-settings-1=widgets_access%3Doff%26uploader%3D127; wp-settings-time-1=1334005698; wordpress_logged_in_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C68a0d9df0911bd2b367c681b0981811a Pragma: no-cache Cache-Control: no-cache Response HTTP/1.1 200 OK Date: Mon, 09 Apr 2012 22:25:01 GMT Server: Apache/2.2.20 (Ubuntu) X-Powered-By: PHP/5.3.6-13ubuntu3.6 Set-Cookie: bb2_screener_=1334010301+127.0.0.1; path=/ Expires: Thu, 19 Nov 1981 08:52:00 GMT Last-Modified: Mon, 09 Apr 2012 22:25:01 GMT Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Pragma: no-cache X-Frame-Options: SAMEORIGIN Vary: Accept-Encoding Content-Length: 167804 Content-Type: text/html; charset=UTF-8 <!DOCTYPE html> <!--[if IE 8]> <html xmlns="http://www.w3.org/1999/xhtml" class="ie8" dir="ltr" lang="en-US"> <![endif]--> <!--[if !(IE 8) ]><!--> <html xmlns="http://www.w3.org/1999/xhtml" dir="ltr" lang="en-US"> <!--<![endif]--> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>BulletProof Security ~ htaccess Core &lsaquo; redteam-wp &#8212; WordPress</title> ...[SNIP]... <tr> <td class="bps-table_cell">Browser Compression Supported: <strong>gzip, deflatea7123<script>alert(1)</script>78089b4648b</td> <td>&nbsp;</td> <td class="bps-table_cell">&nbsp;</td> </tr> <tr> ...[SNIP]... -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJPrDi5AAoJEJPBwXYLR9VtZrMP/inAJrfCt8LiQC9DTAjjxtKb 64ufF5HnwxIkVP0iRhIrVB72OoPhgAA/M9G0x1ZtcuImRSSwqBmPRXiXb2FojQMl xA7IM7P36cVdrtvRTZjFGzgC7zCJ40f3n+AJdAqaSzacVZ9E25McD1pZZlXOcdq6 5aMYg3LOXBMBFyrsOu+VenVDa1sbviuT+ZqFTx7DlE6EkXrdmFLHuUS3lUXlsrfK DWlQBbbu98n9OGY/31pPvB73X2Z0K5H+7dz5ySfTjKJLJgy8tjSACX1iIEfv6z9e npWVSBfr9c01GjfY1ACKRx12tPGF8j6xns2qDZOYiP8s/vxlDM/e+2Dpp9x4o8PP 5J2iI+RppJRjHK70BNzEfheXs6g+0BXLXzF7vIxXuVeBqQAodleJhMtbFvKyJ9ki tNdz0ucpBY2zxGpFw6THW2QYLGh9oGN++KP6AI/ZQVIMCuHiD0elQWQLEY2wIr28 FJXghkDZRUxIQZK4uPhHuaQ7E9gecVJm19CDfcaJ2L35iX9YbalfOAbgOyMlIBy3 DkgXLgMYbdeTBBCh3nHZutMsvqsAPndqwhQQ2nWCjQV7wLd69uk6c1LYRx1dIAGs H8YjgFPYhlXDlxTpyo1Nf0bGGNGFGatffhklVmUD4n1kzG2Py1wCYCzNzi3VZYy3 kkbQdNSxkSDQoiREHl/q =cZih -----END PGP SIGNATURE-----