zope: multiple vulnerabilities

From the Debian advisory:

Due to a programming error an authorization method in the StorageServer component of ZEO was not used as an internal method. This allows a malicious client to bypass authentication when connecting to a ZEO server by simply calling this authorization method (CVE-2009-0668).

The ZEO server doesn't restrict the callables when unpickling data received from a malicious client which can be used by an attacker to execute arbitrary python code on the server by sending certain exception pickles. This also allows an attacker to import any importable module as ZEO is importing the module containing a callable specified in a pickle to test for a certain flag (CVE-2009-0668).

The update also limits the number of new object ids a client can request to 100 as it would be possible to consume huge amounts of resources by requesting a big batch of new object ids. No CVE id has been assigned to this.