{ "CVE_data_meta": { "ASSIGNER": "security-advisories@github.com", "ID": "CVE-2021-32807", "STATE": "PUBLIC", "TITLE": "Remote Code Execution via unsafe classes in otherwise permitted modules" }, "affects": { "vendor": { "vendor_data": [ { "product": { "product_data": [ { "product_name": "AccessControl", "version": { "version_data": [ { "version_value": ">= 4.0, < 4.3" }, { "version_value": ">= 5.0, < 5.2" } ] } } ] }, "vendor_name": "zopefoundation" } ] } }, "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": { "description_data": [ { "lang": "eng", "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." } ] }, "impact": { "cvss": { "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" } }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes" } ] } ] }, "references": { "reference_data": [ { "name": "https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgf", "refsource": "CONFIRM", "url": "https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgf" }, { "name": "https://github.com/zopefoundation/AccessControl/commit/b42dd4badf803bb9fb71ac34cd9cb0c249262f2c", "refsource": "MISC", "url": "https://github.com/zopefoundation/AccessControl/commit/b42dd4badf803bb9fb71ac34cd9cb0c249262f2c" }, { "name": "https://github.com/zopefoundation/AccessControl/blob/master/CHANGES.rst#51-2021-07-30", "refsource": "MISC", "url": "https://github.com/zopefoundation/AccessControl/blob/master/CHANGES.rst#51-2021-07-30" } ] }, "source": { "advisory": "GHSA-qcx9-j53g-ccgf", "discovery": "UNKNOWN" } }