CVE-2018-20148 : Security Advisory and Response

WordPress versions prior to 4.9.9 and 5.x prior to 5.0.1 were vulnerable to PHP object injection attacks through manipulated metadata in an XMLRPC call.

Understanding CVE-2018-20148

This CVE highlights a security flaw in WordPress that allowed contributors to execute PHP object injection attacks.

What is CVE-2018-20148?

The vulnerability in WordPress versions prior to 4.9.9 and 5.x prior to 5.0.1 enabled contributors to conduct PHP object injection attacks by leveraging manipulated metadata in an XMLRPC call called wp.getMediaItem. The issue stemmed from mishandling serialized data in the wp_get_attachment_thumb_file function located in wp-includes/post.php and specifically impacted phar:// URLs.

The Impact of CVE-2018-20148

The security flaw in CVE-2018-20148 could be exploited by contributors to perform PHP object injection attacks, potentially leading to unauthorized access and manipulation of data within affected WordPress installations.

Technical Details of CVE-2018-20148

WordPress versions prior to 4.9.9 and 5.x prior to 5.0.1 were susceptible to PHP object injection attacks due to mishandling of serialized data.

Vulnerability Description

Contributors could exploit the vulnerability by using manipulated metadata in an XMLRPC call, wp.getMediaItem, allowing them to execute PHP object injection attacks.

Affected Systems and Versions

WordPress versions prior to 4.9.9
WordPress 5.x versions prior to 5.0.1

Exploitation Mechanism

The vulnerability was exploited through the mishandling of serialized data in the wp_get_attachment_thumb_file function in wp-includes/post.php, particularly affecting phar:// URLs.

Mitigation and Prevention

To address CVE-2018-20148, immediate steps and long-term security practices are crucial.

Immediate Steps to Take

Update WordPress to version 4.9.9 or 5.0.1 to patch the vulnerability.
Monitor for any unauthorized access or suspicious activities on the WordPress site.

Long-Term Security Practices

Regularly update WordPress and plugins to the latest versions to prevent known vulnerabilities.
Implement strong access controls and user permissions to limit the impact of potential security breaches.
Conduct security audits and penetration testing to identify and address any security weaknesses.

Patching and Updates

Apply security patches promptly as they become available to ensure the WordPress installation is protected against known vulnerabilities.