CVE-2021-32811 Remote Code Execution via Script (Python) objects under Python 3
Attackers with Manager role can execute arbitrary code via Script objects in Zope if untrusted users have web editing access.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-32811?
CVE-2021-32811 is a high-severity code injection vulnerability in zopefoundation Zope, published on 2 Aug 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Zope is an open-source web application server. Zope versions prior to versions 4.6.3 and 5.3 have a remote code execution security issue. In order to be affected, one must use Python 3 for one's Zope deployment, run Zope 4 below version 4.6.3 or Zope 5 below version 5.3, and have the optional `Products.PythonScripts` add-on package installed. By default, one must 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 are at risk. Zope releases 4.6.3 and 5.3 are not vulnerable. As a workaround, a site administrator can restrict adding/editing Script (Python) objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.
Which versions are affected by CVE-2021-32811?
6 open source packages ship an affected version, including zope, Zope and accesscontrol. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
zope PyPI | From 4.0 | 4.6.3, 5.3 |
zope PyPI | From 4.0 | 4.6.3 |
zope PyPI | From 5.0 | 5.3 |
Zope PyPI | From 4.0 | 4.6.3 |
Zope PyPI | From 5.0 | 5.3 |
accesscontrol PyPI | From 4.0 | 4.3, 5.2 |
Products include Zope Accesscontrol, Zope Zope.
How do I fix CVE-2021-32811?
Upgrade zope to a fixed version for your release line: 4.6.3 or 5.3.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2021-32811 being exploited?
There is no known exploitation of CVE-2021-32811 in the wild and no public exploit code.
Other vulnerabilities in zopefoundation Zope
Sources
Also known as GHSA-g4gq-j4p2-j8fr, PYSEC-2021-368, PYSEC-2021-370, UBUNTU-CVE-2021-32811.