CVE-2021-32807
Assigner: GitHub_M
Published: 2021-07-30T21:20:11
State: PUBLISHED
affected: product: AccessControl
vendor: zopefoundation
versions: status: affected
version: >= 4.0, < 4.3
status: affected
version: >= 5.0, < 5.2
descriptions: value: The module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of `Script (Python)` objects. The policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution. By 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 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7. As a workaround, 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.
metrics: cvssV3_1: attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 4.4
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: HIGH
privilegesRequired: HIGH
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
version: 3.1
problemTypes: descriptions: cweId: CWE-915
description: CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes
type: CWE
source: advisory: GHSA-qcx9-j53g-ccgf
discovery: UNKNOWN
title: Remote Code Execution via unsafe classes in otherwise permitted modules