Stefan Schurtz has discovered some vulnerabilities in the Count Per Day plugin for WordPress, which can be exploited by malicious people to conduct cross-site scripting attacks.

Input passed via multiple parameters to wp-content/plugins/count-per-day/userperspan.php is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.

List of affected scripts and parameters:
http://[host]/wp-content/plugins/count-per-day/userperspan.php?page
http://[host]/wp-content/plugins/count-per-day/userperspan.php?datemin
http://[host]/wp-content/plugins/count-per-day/userperspan.php?datemax

The vulnerabilities are confirmed in version 3.1.1. Prior versions may also be affected.

Solution
Update to version 3.2.

Provided and/or discovered by
Stefan Schurtz

Changelog
Further details available to Secunia VIM customers

Original Advisory
Count Per Day:
http://wordpress.org/extend/plugins/count-per-day/changelog/
http://plugins.trac.wordpress.org/changeset/571926/count-per-day#file22

Stefan Schurtz:
http://www.darksecurity.de/advisories/2012/SSCHADV2012-015.txt

Deep Links
Links available to Secunia VIM customers