CVE-2023-29528 : Security Advisory and Response

This article provides detailed information about CVE-2023-29528, a critical vulnerability related to Cross-site Scripting in org.xwiki.commons:xwiki-commons-xml.

Understanding CVE-2023-29528

CVE-2023-29528 is a Cross-site Scripting vulnerability found in XWiki Commons, common technical libraries used across various XWiki projects. The vulnerability arises from the "restricted" mode of the HTML cleaner, allowing for the injection of arbitrary HTML code and cross-site scripting via invalid HTML comments.

What is CVE-2023-29528?

XWiki Commons are technical libraries common to several other top-level XWiki projects. The issue in this CVE allows the injection of arbitrary HTML code and cross-site scripting via invalid HTML comments, impacting the confidentiality, integrity, and availability of XWiki instances.

The Impact of CVE-2023-29528

Exploitation of this vulnerability can lead to JavaScript injection and execution in the context of a user session, potentially enabling server-side code execution with programming rights. This poses a significant risk to the security and stability of XWiki instances.

Technical Details of CVE-2023-29528

The vulnerability was identified with a CVSS v3.1 base score of 9.1, indicating a critical severity level. The attack complexity is low, requiring low privileges and user interaction, with a high impact on confidentiality, integrity, and availability of affected systems.

Vulnerability Description

The issue stemmed from the "restricted" mode of the HTML cleaner in XWiki, allowing for the injection of arbitrary HTML code and cross-site scripting via invalid HTML comments.

Affected Systems and Versions

XWiki Commons versions ranging from >= 4.2-milestone-1 to < 14.10 are affected by this vulnerability.

Exploitation Mechanism

When a privileged user with programming rights visits a malicious comment in XWiki, the injected JavaScript code is executed within the user session, potentially leading to server-side code execution.

Mitigation and Prevention

It is crucial to take immediate steps to address and mitigate the CVE-2023-29528 vulnerability to enhance the security of XWiki instances.

Immediate Steps to Take

Upgrade to XWiki version 14.10 or higher, as this version includes the necessary patch to remove HTML comments in restricted mode and prevent code injection.

Long-Term Security Practices

Implement regular security audits, stay informed about security advisories, and follow best practices to secure XWiki installations.

Patching and Updates

Ensure timely application of security patches and updates provided by XWiki to address known vulnerabilities and strengthen system security.