CVE-2023-38490 : What You Need to Know

A detailed overview of CVE-2023-38490 focusing on the Kirby XML External Entity (XXE) vulnerability in the XML data handler.

Understanding CVE-2023-38490

This section provides insight into the vulnerability, its impact, technical details, and mitigation steps.

What is CVE-2023-38490?

CVE-2023-38490 involves an XML External Entity (XXE) vulnerability in Kirby versions prior to 3.5.8.3, 3.6.6.3, 3.7.5.2, 3.8.4.1, and 3.9.6. It affects Kirby sites utilizing the

Xml

data handler or the

Xml::parse()

method in site or plugin code.

The Impact of CVE-2023-38490

XML External Entities (XXE) allow including data from external files in XML structures. Exploitation can lead to arbitrary file disclosure or server-side request forgery, potentially exposing confidential data.

Technical Details of CVE-2023-38490

This section delves into the vulnerability description, affected systems, versions, and exploitation mechanism.

Vulnerability Description

The vulnerability arises due to the processing of external entities during XML parsing using the

Xml::parse()

method. This method enables XXE, posing a risk in handling external XML files.

Affected Systems and Versions

Kirby versions < 3.5.8.3 and between 3.6.0 - 3.9.6 are impacted by the XXE vulnerability if employing XML parsing in site or plugin code.

Exploitation Mechanism

Attackers can manipulate external entities in XML files processed by Kirby's

Xml::parse()

method, potentially leading to data disclosure or server-side actions.

Mitigation and Prevention

This section focuses on immediate steps to take, long-term security practices, and patching.

Immediate Steps to Take

Update affected Kirby instances to versions 3.5.8.3, 3.6.6.3, 3.7.5.2, 3.8.4.1, or 3.9.6 to mitigate the XXE vulnerability. Avoid XML parsing in site or plugin code unless necessary.

Long-Term Security Practices

Regularly monitor for security advisories and updates from Kirby. Implement secure coding practices and restrict XML entity processing to trusted sources.

Patching and Updates

Refer to Kirby releases 3.5.8.3, 3.6.6.3, 3.7.5.2, 3.8.4.1, and 3.9.6, where the

LIBXML_NOENT

constant has been removed to prevent XXE vulnerabilities.