Cross-site scripting (XSS) vulnerability in PortalTransforms in Plone 2.1 through 3.3.4 before hotfix 20100612 allows remote attackers to inject arbitrary web script or HTML via the safe_html transform.
http://www.securityfocus.com/bid/40999
http://secunia.com/advisories/40270
http://plone.org/products/plone/security/advisories/cve-2010-unassigned-html-injection-in-safe_html