CVE-2021-32811Network attack vector

Remote code execution via exposed string Formatter

Published Aug 2, 2021 · Updated Aug 3, 2024

Remote code execution in Zope 4.0 through 4.6.2 and 5.0 through 5.2 allows remote authenticated users to execute Python code. AccessControl exposes string.Formatter to restricted Script (Python) objects, whose code can subclass it to reach unsafe Python libraries. Exploitation requires Python 3, Products.PythonScripts, and permission for untrusted users to edit scripts, which the default Manager-only policy denies.

CVSS severity7.5
High
EPSS probability2.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in Zope 4.0 through 4.6.2 and 5.0 through 5.2 allows remote authenticated users to execute Python code. AccessControl exposes string.Formatter to restricted Script (Python) objects, whose code can subclass it to reach unsafe Python libraries. Exploitation requires Python 3, Products.PythonScripts, and permission for untrusted users to edit scripts, which the default Manager-only policy denies.

The record

CVE
CVE-2021-32811
Published
Aug 2, 2021
Updated
Aug 3, 2024
Vendor
Zope Foundation
Product
Zope
Classifications
CWE-1321, CWE-915, T1059.006
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 4.0, < 4.6.3
  2. Affected versionversion=>= 5.0, < 5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zope Foundation · Zopeversion=>= 4.0, < 4.6.3; version=>= 5.0, < 5.3

Published CVSS scores

7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.5GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes
T1059.006Command and Scripting Interpreter: Python

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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