Remote Code Execution (RCE) Affecting zope package, versions [4.0, 4.6.3)[5.0, 5.3)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
1.46% (87th percentile)

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  • Snyk IDSNYK-PYTHON-ZOPE-1536787
  • published6 Aug 2021
  • disclosed5 Aug 2021
  • creditUnknown

Introduced: 5 Aug 2021

CVE-2021-32811  (opens in a new tab)
CWE-94  (opens in a new tab)

How to fix?

Upgrade Zope to version 4.6.3, 5.3 or higher.

Overview

Zope is a Zope application server / web framework

Affected versions of this package are vulnerable to Remote Code Execution (RCE). The optional add-on package Products.PythonScripts adds Script (Python) to the list of content items a user can add to the Zope object database. Inside these scripts users can write Python code that is executed when rendered through the web. The code environment in these script objects is limited, it relies on the RestrictedPython package to provide a "safe" subset of Python instructions as well as the AccessControl package that defines security policies for execution in the context of a Zope application.

Recently the AccessControl package was updated to fix a remote code execution security issue. A link to the security advisory is provided in the References section below. The bug tightens the AccessControl security policies for Zope by blocking access to unsafe classes inside the Python string module.

You are only affected if the following are true:

  • You use Python 3 for your Zope deployment (Zope 4 on Python 2 is not affected)
  • You run Zope 4 below version 4.6.3 or Zope 5 below version 5.3
  • You have installed the optional Products.PythonScripts add-on package

By default, you need to have the admin-level Zope "Manager" role to add or edit Script (Python) objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk.

References

CVSS Scores

version 3.1