ZCatalog plug-in index support capability for Zope 2.4.0 through 2.5.1 allows anonymous users and untrusted code to bypass access restrictions and call arbitrary methods of catalog indexes.
http://www.zope.org/Products/Zope/Hotfix_2002-06-14/security_alert
http://www.securityfocus.com/bid/5812
http://www.redhat.com/support/errata/RHSA-2002-060.html