CVE-2021-32674

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 5.21 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 to fix CVE-2021-32674

To remediate CVE-2021-32674, upgrade the affected package to a fixed version below.

• —upgrade to 4.6.1 or later
• —upgrade to 5.2.1 or later
• —upgrade to 1d897910139e2c0b11984fc9b78c1da1365bec21 or later

Is CVE-2021-32674 being exploited?

Low — EPSS is 1.6%, meaning exploitation activity has not been observed at scale.

Affected packages (3)

• from 0, < 4.6.1