The SimpleXMLRPCServer library module in Python 2.2, 2.3 before 2.3.5, and 2.4, when used by XML-RPC servers that use the register_instance method to register an object without a _dispatch method, allows remote attackers to read or modify globals of the associated module, and possibly execute arbitrary code, via dotted attributes.
https://exchange.xforce.ibmcloud.com/vulnerabilities/19217
http://www.trustix.org/errata/2005/0003/
http://www.securityfocus.com/bid/12437
http://www.redhat.com/support/errata/RHSA-2005-108.html