Check Point Software Technologies - Vulnerability Discovery Team (VDT) http://www.checkpoint.com/defense/ Related Posts WordPress Plugin Cross Site Scripting Vulnerability CVE-2011-0760 INTRODUCTION The WordPress Related Posts Plugin (http://WordPress.org/extend/plugins/wp-related-posts/) shows the posts related to others posts. This advisory describes multiple Stored Cross Site Scripting (XSS) vulnerabilities and one Cross Site Request Forgery (CSRF) vulnerability on the plugin. As a result, an attacker can gain elevated access privileges to sensitive page content, session cookies, and a variety of other information maintained by the browser on behalf of the WordPress administrator user. Furthermore, the attacker can perform actions with administrative powers. This problem was confirmed in the latest version of the plugin, other versions maybe also affected. CVSS Scoring System The CVSS score is: 6.4 Base Score: 6.7 Temporal Score: 6.4 We used the following values to calculate the scores: Base score is: AV:N/AC:L/Au:N/C:C/I:C/A:N Temporal score is: E:F/RL:U/RC:C DETAILS The plugin's configuration page is vulnerable to Stored Cross Site Scripting. The three fields wp_relatedposts_ title, wp_relatedposts_num and wp_relatedposts_type are received through POST or GET and included on the response page with little sanitization. The vulnerable code is shown next: 158: 159: Title: 160: 161: 162: 163: Number posts: 164: 165: 166: 167: Related on: 168: 169: 174: --- Another vulnerable piece of code is the one which prints the related posts list. The title (received through the parameter wp_relatedposts_title is included with little sanitization into suchs lists. The vulnerable code is shown next: --- 79: $relatedpost.= '


' . $options['title'] . '