Remote Code Execution via unsafe classes in otherwise permitted modules
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 4.3, 5.2
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- zopefoundation AccessControl
From 4.0 · fixed in 4.3; From 5.0 · fixed in 5.2
- zopePyPI
From 4.0 · fixed in 4.3; From 5.0 · fixed in 5.2
- accesscontrolPyPI
From 4.0 · fixed in 4.3; From 5.0 · fixed in 5.2
- accesscontrolPyPI
From 4.0 · fixed in 4.3
- accesscontrolPyPI
From 5.0 · fixed in 5.2
- zopePyPI
From 4.0 · fixed in 4.3
- zopePyPI
From 5.0 · fixed in 5.2