CVE-2021-32633Public exploitNetwork attack vector

Remote code execution via unsafe underscore traversal

Published May 21, 2021 · Updated Aug 3, 2024

Path traversal in Zope before 4.6 and 5.0 through versions before 5.2 allows remote authenticated users to execute code through TAL expressions. PageTemplates traversal accepts underscore-prefixed path elements, allowing expressions to reach restricted attributes and indirectly access unsafe Python modules. Exploitation requires permission to add or edit Zope Page Templates through the web; that permission is limited to the Manager role by default.

CVSS severity6.8
Medium
EPSS probability1.86%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Zope before 4.6 and 5.0 through versions before 5.2 allows remote authenticated users to execute code through TAL expressions. PageTemplates traversal accepts underscore-prefixed path elements, allowing expressions to reach restricted attributes and indirectly access unsafe Python modules. Exploitation requires permission to add or edit Zope Page Templates through the web; that permission is limited to the Manager role by default.

The record

CVE
CVE-2021-32633
Published
May 21, 2021
Updated
Aug 3, 2024
Vendor
Zope Foundation
Product
Zope
Classifications
CWE-22, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 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=< 4.6
  2. Affected versionversion=>= 5.0, < 5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zope Foundation · Zopeversion=< 4.6; version=>= 5.0, < 5.2

Published CVSS scores

6.5NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.8GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

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 exploitPublished

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

Public exploit references

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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