CVE-2021-32811: 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 ...

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.

Metrics

CVSS 3.1

7.2/10

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.28%

80.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Zope	Accesscontrol	>= 4.0, < 4.3
Zope	Accesscontrol	>= 5.0, < 5.2
Zope	Zope	>= 4.0, < 4.6.3
Zope	Zope	>= 5.0, < 5.3

References

https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgfThird Party Advisory
https://github.com/zopefoundation/Zope/commit/f72a18dda8e9bf2aedb46168761668464a4be988Patch, Third Party Advisory
https://github.com/zopefoundation/Zope/security/advisories/GHSA-g4gq-j4p2-j8frThird Party Advisory
https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgfThird Party Advisory
https://github.com/zopefoundation/Zope/commit/f72a18dda8e9bf2aedb46168761668464a4be988Patch, Third Party Advisory
https://github.com/zopefoundation/Zope/security/advisories/GHSA-g4gq-j4p2-j8frThird Party Advisory

Timeline

Published: Aug 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32811?

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.

How severe is CVE-2021-32811?

CVE-2021-32811 has a CVSS score of 7.2/10 (HIGH severity). The EPSS model estimates a 2.28% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32811?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.