CVE-2021-32811 Explained : Impact and Mitigation

Zope is an open-source web application server with versions 4.6.3 and 5.3 free from a remote code execution security issue under Python 3. However, Zope versions below 4.6.3 and 5.3 are vulnerable if running Python 3 and having the

Products.PythonScripts

add-on.

Understanding CVE-2021-32811

This CVE identifies a remote code execution vulnerability in Zope versions prior to 4.6.3 and 5.3, affecting deployments using Python 3 and the optional

Products.PythonScripts

add-on.

What is CVE-2021-32811?

Zope versions below 4.6.3 and 5.3 have a security flaw allowing remote code execution. Only setups with Python 3, running Zope versions below 4.6.3 or 5.3, and the

Products.PythonScripts

add-on are at risk.

The Impact of CVE-2021-32811

With a CVSS base score of 7.5 (High Severity), this vulnerability has a significant impact on confidentiality, integrity, and availability of affected systems.

Technical Details of CVE-2021-32811

The issue stems from improperly controlled modification of dynamically-determined object attributes, classified under CWE-915, and requires low privileges for exploitation.

Vulnerability Description

Zope versions prior to 4.6.3 and 5.3 are susceptible to remote code execution, posing a high risk of unauthorized access and data compromise.

Affected Systems and Versions

Systems running Zope versions >= 4.0, < 4.6.3, and >= 5.0, < 5.3 with Python 3 and the

Products.PythonScripts

add-on are impacted.

Exploitation Mechanism

Exploiting this vulnerability requires minimal privileges and network access, with high impacts on system availability, confidentiality, and integrity.

Mitigation and Prevention

To secure systems against CVE-2021-32811, immediate steps should be taken along with a robust long-term security strategy.

Immediate Steps to Take

Site administrators should restrict the addition/editing of Script (Python) objects via web interfaces to trusted users only, removing the Zope Manager role from untrusted users.

Long-Term Security Practices

Implement strict user/role permissions within Zope deployments and regularly review and update security configurations to prevent unauthorized access.

Patching and Updates

Ensure Zope deployments are updated to versions 4.6.3 or 5.3 to mitigate the vulnerability. Regularly apply security patches and stay informed of future security advisories from Zope developers.