From 3baf1d10429ae4ab503e0b96daeb88cfb860e54c Mon Sep 17 00:00:00 2001 From: Tim Graham Date: Tue, 3 Sep 2013 07:48:03 -0400 Subject: [PATCH] Fixed #21002 -- Documented JSON session serialization requires string keys Thanks jeroen.pulles at redslider.net for the report. --- docs/releases/1.6.txt | 7 +++++-- docs/topics/http/sessions.txt | 20 +++++++++++++++++--- 2 files changed, 22 insertions(+), 5 deletions(-) diff --git a/docs/releases/1.6.txt b/docs/releases/1.6.txt index 1e71e1db2e..72d4df0fee 100644 --- a/docs/releases/1.6.txt +++ b/docs/releases/1.6.txt @@ -745,7 +745,8 @@ Default session serialization switched to JSON Historically, :mod:`django.contrib.sessions` used :mod:`pickle` to serialize session data before storing it in the backend. If you're using the :ref:`signed cookie session backend` and :setting:`SECRET_KEY` is -known by an attacker, the attacker could insert a string into his session +known by an attacker (there isn't an inherent vulnerability in Django that +would cause it to leak), the attacker could insert a string into his session which, when unpickled, executes arbitrary code on the server. The technique for doing so is simple and easily available on the internet. Although the cookie session storage signs the cookie-stored data to prevent tampering, a @@ -759,7 +760,9 @@ For backwards compatibility, this setting defaulted to using :mod:`pickle` in Django 1.5.3, but we've changed the default to JSON in 1.6. If you upgrade and switch from pickle to JSON, sessions created before the upgrade will be lost. While JSON serialization does not support all Python objects like -:mod:`pickle` does, we highly recommend using JSON-serialized sessions. See the +:mod:`pickle` does, we highly recommend using JSON-serialized sessions. Also, +as JSON requires string keys, you will likely run into problems if you are +using non-string keys in ``request.session``. See the :ref:`session_serialization` documentation for more details. Miscellaneous diff --git a/docs/topics/http/sessions.txt b/docs/topics/http/sessions.txt index 47be4c6684..8bef7f2ee5 100644 --- a/docs/topics/http/sessions.txt +++ b/docs/topics/http/sessions.txt @@ -314,7 +314,8 @@ Session serialization Before version 1.6, Django defaulted to using :mod:`pickle` to serialize session data before storing it in the backend. If you're using the :ref:`signed cookie session backend` and :setting:`SECRET_KEY` is -known by an attacker, the attacker could insert a string into his session +known by an attacker (there isn't an inherent vulnerability in Django that +would cause it to leak), the attacker could insert a string into his session which, when unpickled, executes arbitrary code on the server. The technique for doing so is simple and easily available on the internet. Although the cookie session storage signs the cookie-stored data to prevent tampering, a @@ -338,8 +339,21 @@ Bundled Serializers .. class:: serializers.JSONSerializer A wrapper around the JSON serializer from :mod:`django.core.signing`. Can - only serialize basic data types. See the :ref:`custom-serializers` section - for more details. + only serialize basic data types. + + In addition, as JSON supports only string keys, note that using non-string + keys in ``request.session`` won't work as expected:: + + >>> # initial assignment + >>> request.session[0] = 'bar' + >>> # subsequent requests following serialization & deserialization + >>> # of session data + >>> request.session[0] # KeyError + >>> request.session['0'] + 'bar' + + See the :ref:`custom-serializers` section for more details on limitations + of JSON serialization. .. class:: serializers.PickleSerializer