CVE Vulnerability

CVE-2021-32807

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.

6.5 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 8 / Impact : 6.4

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

Scope

7.2 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 1.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/zopefoundation/AccessControl/blob/master/CHANGES.rst#51-2021-07-30 Release Notes Third Party Advisory
https://github.com/zopefoundation/AccessControl/commit/b42dd4badf803bb9fb71ac34cd9cb0c249262f2c Patch Third Party Advisory
https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgf Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:zope:accesscontrol:*:*:*:*:*:*:*:*
cpe:2.3:a:zope:accesscontrol:*:*:*:*:*:*:*:*
Information

Published : 2021-07-30 10:15

Updated : 2022-12-02 07:36

NVD link : CVE-2021-32807

Mitre link : CVE-2021-32807

Products Affected
No products.
CWE
CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')