Zope hotfix: ZClass permission mapping bug
This hotfix addresses an important security issue that affects all Zope versions up to and including Zope 2.3.2.
The issue is related to ZClasses in that any user can visit a ZClass declaration and change the ZClass permission mappings for methods and other objects defined within the ZClass, possibly allowing for unauthorized access within the Zope instance.
We highly recommend that any Zope site running versions of Zope up to and including 2.3.2 have this hotfix product installed to mitigate this issue. Further releases of Zope 2.3 (as well as Zope 2.4) will contain a fix for the issue, at which time the hotfix can be removed.
http://www.zope.org/Products/Zope/Hotfix_2001-05-01/Hotfix_2001-05-01.tgz