Many XML/RPC servers based on Python / Ruby seem to be vulnerable to a simple Denial of Service where transmitting a large amount of data (circa 4 MB) results in them utilizing 100% of the CPU and apparently never recovering.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/37236/python_xmlrpc_dos.txt
Source: https://packetstormsecurity.com/files/37236/python_xmlrpc_dos.txt.html