CVE-2020-28736 Explained : Impact and Mitigation

Plone before 5.2.3 allows XXE attacks via a feature that is protected by an unapplied permission of plone.schemaeditor.ManageSchemata (therefore, only available to the Manager role).

Understanding CVE-2020-28736

Plone before version 5.2.3 is vulnerable to XXE attacks due to inadequate permission settings.

What is CVE-2020-28736?

CVE-2020-28736 is a vulnerability in Plone versions prior to 5.2.3 that enables XML External Entity (XXE) attacks through a specific feature.

The Impact of CVE-2020-28736

This vulnerability allows attackers to exploit XXE attacks, potentially leading to unauthorized access to sensitive data or server-side request forgery (SSRF) attacks.

Technical Details of CVE-2020-28736

Plone before 5.2.3 is susceptible to XXE attacks due to a specific permission misconfiguration.

Vulnerability Description

The vulnerability arises from a feature in Plone that lacks proper permission settings, specifically in plone.schemaeditor.ManageSchemata, which is only accessible to users with the Manager role.

Affected Systems and Versions

Product: Plone
Vendor: N/A
Versions affected: All versions before 5.2.3

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating XML input to trigger XXE attacks, potentially leading to data exposure or SSRF.

Mitigation and Prevention

It is crucial to take immediate steps to mitigate the risks posed by CVE-2020-28736.

Immediate Steps to Take

Update Plone to version 5.2.3 or later to patch the vulnerability.
Restrict access to sensitive features to authorized users only.

Long-Term Security Practices

Regularly review and update permission settings to prevent unauthorized access.
Educate users on secure coding practices to avoid introducing vulnerabilities.

Patching and Updates

Ensure timely installation of security patches and updates to protect against known vulnerabilities.