CVE-2021-32811

Remote Code Execution via Script (Python) objects under Python 3

HIGH
7.2
CVSS Score
Published: August 2, 2021 at 09:55 PM UTC
Updated: June 17, 2026 at 03:53 AM UTC
3 products affected across 2 vendorsZopeAccesscontrolZope

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Severity
HIGH7.2
Exploit prediction
EPSS 2%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.0 ≤ v < 4.35.0 ≤ v < 5.2
Affected range stops below 4.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.2, so it looks safe — our inference, not a vendor statement
4.0 ≤ v < 4.6.35.0 ≤ v < 5.3
Affected range stops below 4.6.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.3, so it looks safe — our inference, not a vendor statement
v < 4.6.3v < 5.3
Affected range stops below 4.6.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-915CWE-1321

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