CVE-2021-32674: Zope is an open-source web application server. This advisory extends the previous advisory at https://github.com/zopefoundation/Zope/security/advisori...

Description

Zope is an open-source web application server. This advisory extends the previous advisory at https://github.com/zopefoundation/Zope/security/advisories/GHSA-5pr9-v234-jw36 with additional cases of TAL expression traversal vulnerabilities. Most Python modules are not available for using in TAL expressions that you can add through-the-web, for example in Zope Page Templates. This restriction avoids file system access, for example via the 'os' module. But some of the untrusted modules are available indirectly through Python modules that are available for direct use. By default, you need to have the Manager role to add or edit Zope Page Templates through the web. Only sites that allow untrusted users to add/edit Zope Page Templates through the web are at risk. The problem has been fixed in Zope 5.2.1 and 4.6.1. The workaround is the same as for https://github.com/zopefoundation/Zope/security/advisories/GHSA-5pr9-v234-jw36: A site administrator can restrict adding/editing Zope Page Templates through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing Zope Page Templates through the web should be restricted to trusted users only.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.57%

72.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Zope	Zope	< 4.6.1
Zope	Zope	>= 5.0.0, < 5.2.1

References

https://github.com/zopefoundation/Zope/commit/1d897910139e2c0b11984fc9b78c1da1365bec21Patch, Third Party Advisory
https://github.com/zopefoundation/Zope/security/advisories/GHSA-5pr9-v234-jw36Third Party Advisory
https://github.com/zopefoundation/Zope/security/advisories/GHSA-rpcg-f9q6-2mq6Third Party Advisory
https://pypi.org/project/Zope/Product
https://github.com/zopefoundation/Zope/commit/1d897910139e2c0b11984fc9b78c1da1365bec21Patch, Third Party Advisory
https://github.com/zopefoundation/Zope/security/advisories/GHSA-5pr9-v234-jw36Third Party Advisory
https://github.com/zopefoundation/Zope/security/advisories/GHSA-rpcg-f9q6-2mq6Third Party Advisory
https://pypi.org/project/Zope/Product

Timeline

Published: Jun 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32674?

Zope is an open-source web application server. This advisory extends the previous advisory at https://github.com/zopefoundation/Zope/security/advisories/GHSA-5pr9-v234-jw36 with additional cases of TAL expression traversal vulnerabilities. Most Python modules are not available for using in TAL expressions that you can add through-the-web, for example in Zope Page Templates. This restriction avoids file system access, for example via the 'os' module. But some of the untrusted modules are available indirectly through Python modules that are available for direct use. By default, you need to have the Manager role to add or edit Zope Page Templates through the web. Only sites that allow untrusted users to add/edit Zope Page Templates through the web are at risk. The problem has been fixed in Zope 5.2.1 and 4.6.1. The workaround is the same as for https://github.com/zopefoundation/Zope/security/advisories/GHSA-5pr9-v234-jw36: A site administrator can restrict adding/editing Zope Page Templates through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing Zope Page Templates through the web should be restricted to trusted users only.

How severe is CVE-2021-32674?

CVE-2021-32674 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.57% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32674?

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.