CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:P/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
82.9%
Background: The optional add-on package Products.PythonScripts
adds Script (Python)
to the list of content items a user can add to the Zope object database. Inside these scripts users can write Python code that is executed when rendered through the web. The code environment in these script objects is limited, it relies on the RestrictedPython
package to provide a “safe” subset of Python instructions as well as the AccessControl
package that defines security policies for execution in the context of a Zope application.
Recently the AccessControl
package was updated to fix a remote code execution security issue. A link to the security advisory is provided in the References section below. The bug tightens the AccessControl
security policies for Zope by blocking access to unsafe classes inside the Python string
module.
You are only affected if the following are true:
Products.PythonScripts
add-on packageBy default, you need to 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 - which would be a very unusual configuration to begin with - are at risk.
The problem has been fixed in AccessControl
versions 4.3 and 5.2. Zope releases 4.6.3 and 5.3 now require these new AccessControl
releases.
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.
If you have any questions or comments about this advisory:
github.com/advisories/GHSA-g4gq-j4p2-j8fr
github.com/pypa/advisory-database/tree/main/vulns/zope/PYSEC-2021-368.yaml
github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgf
github.com/zopefoundation/Zope/commit/869f947e586517566509e0ccdd4d99b60704cc02
github.com/zopefoundation/Zope/commit/f72a18dda8e9bf2aedb46168761668464a4be988
github.com/zopefoundation/Zope/security/advisories/GHSA-g4gq-j4p2-j8fr
nvd.nist.gov/vuln/detail/CVE-2021-32811
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:L/Au:S/C:P/I:P/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
82.9%