Security concern for rule sets

[vvoovv]

A rule set downloaded from the web, can exhibit malicious activity.

The solution is to block import of some python modules (e.g. httplib) and override some builtin functions (e.g. open()).

Keywords: sys.meta_path, find_module, load_module
Recipe: http://xion.org.pl/2012/05/06/hacking-python-imports/

class ImportBlocker(object):
def init(self, *args):
self.module_names = args

def find_module(self, fullname, path=None):
    if fullname in self.module_names:
        return self
    return None

def load_module(self, name):
    raise ImportError("%s is blocked and cannot be imported" % name)

import sys
sys.meta_path = [ImportBlocker("httplib")]