Notes about Python Security.

== tav's jail ==

http://tav.espians.com/a-challenge-to-break-python-security.html

 * Remove evil attributes like frame.f_globals or object.__subclasses__
 * Remove evil builtins like compile(), import() or reload()

== Zope security ==

http://svn.zope.org/zope.security/trunk/src/zope/security/

 * Sandboxing
 * Object proxies

== Taint mode ==

Nicole King at one point wrote a taint mode for CPython 3.0, but the site (http://www.cats-muvva.net/software/) is no longer functioning.

Problems:
 * amaury: ''The patch is indeed huge!''
 * fijall: ''it seems that every function that returns a PyObject must be modified''
 * fijall: ''need to patch (...) all places that might modify anything. (All side effects)''

=> ncoghlan: ''PyPy is still a *much* better platform for that kind of experimentation than CPython''

See also the presentation: [[http://us.pycon.org/common/talkdata/PyCon2007/062/PyCon_2007.pdf|Securing Python: Controlling the abilities of the interpreter]], PyCon US 2007, Brett Cannon and Eric Wohlstadter

Related issue: [[http://bugs.python.org/issue500698|Taint a la Perl?]].

== Python Security Response Team ==

Some members:
 * Brett Cannon

Email: security AT python.org

== Controlling Access to Resources Within The Python Interpreter ==

 * URL: [[http://sayspy.blogspot.com/2007/04/python-security-paper-online.html|Python security paper online]]
 * Paper: [[http://www.cs.ubc.ca/~drifty/papers/python_security.pdf|Controlling Access to Resources Within The Python Interpreter]], Brett Cannon and Eric Wohlstadter, University of British Columbia

== Sandboxing ==

 * PyPy project: [[http://codespeak.net/pypy/dist/pypy/doc/sandbox.html|PyPy's sandboxing features]].
 * [[http://mail.python.org/pipermail/python-dev/2008-September/082475.html|CapPython]] is an object-capability subset of Python, inspired by Joe-E and Caja/Cajita, which are object-capability subsets of Java and Javascript respectively.
 * SandboxedPython
 * [[How can I run an untrusted Python script safely (i.e. Sandbox)]]
 * [[http://mail.python.org/pipermail/python-dev/2009-June/090038.html|CPython in the web browser under Native Client]]

== Unsafe modules ==

 * os.kill(), os.chown(), os.unlink(), ...
 * imageop: many bugs
   * [[http://bugs.python.org/issue1179|CVE-2007-4965: Integer overflow in imageop module]] (2007-09 .. 2008-08)
   * [[http://bugs.python.org/issue4317|Buffer overflow in imageop module]] (rgb2rgb8): fixed in Python 2.6.1 and Python 3.0

== Fuzzing ==

Victor Stinner wrote a fuzzer called [[https://github.com/clem1/segvault/tree/master/fusil|Fusil]] to test Python. It already helped to fix many bugs. fusil-python works on Python 2.4 .. 3.0.

Fusil was also used on PyPy ([[http://morepypy.blogspot.com/2008/07/finding-bugs-in-pypy-with-fuz.html|Finding Bugs in PyPy with a Fuzzer]]).