source: http://www.securityfocus.com/bid/32267/info

Zope is prone to multiple remote denial-of-service vulnerabilities.

Remote attackers can exploit this issue to cause the Zope server to halt or to consume excessive server resources, resulting in denial-of-service conditions.

These issues affect Zope 2.7.0 through 2.11.2. 

To halt the application:
raise SystemExit

To consume excessive resources:
return 'foo'.encode('test.testall')