Description
WordPress is prone to a cross-site scripting vulnerability because it fails to properly sanitize user-supplied input. An attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site. This can allow the attacker to steal cookie-based authentication credentials and launch other attacks. WordPress versions prior to 3.3.2 are vulnerable.
Remediation
Update to WordPress version 3.3.2 or latest
References
http://seclists.org/fulldisclosure/2012/Nov/51
http://packetstormsecurity.org/files/118009/wpswfupload-xss.txt
Related Vulnerabilities
WordPress Plugin Fancy Gallery Cross-Site Scripting (1.5.12)
WordPress Plugin Rucy Cross-Site Request Forgery (0.4.4)
WordPress Plugin Loginizer Cross-Site Scripting (1.3.9)
WordPress Plugin Shopello API Cross-Site Scripting (2.9.0)
WordPress Plugin FormCraft-Contact Form Builder Cross-Site Request Forgery (1.2.1)