PythonScripts in Zope 2 2.11.2 and earlier, as used in Conga and other products, allows remote authenticated users to cause a denial of service (resource consumption or application halt) via certain (1) raise or (2) import statements.
https://bugs.launchpad.net/zope2/+bug/257276
https://bugs.launchpad.net/zope2/+bug/257269
http://www.zope.org/Products/Zope/Hotfix-2008-08-12/README.txt
http://www.zope.org/Products/Zope/Hotfix-2008-08-12/Hotfix_20080812-1.1.0.tar.gz
http://www.vupen.com/english/advisories/2008/2418
http://openwall.com/lists/oss-security/2008/11/12/2