CVE-2023-5561 Explained : Impact and Mitigation

In October 2023, WPScan published CVE-2023-5561 highlighting the vulnerability in WordPress versions below 6.3.2, allowing unauthenticated users to access the email addresses of public post authors.

Understanding CVE-2023-5561

This CVE addresses an information disclosure vulnerability in the WordPress platform that could potentially expose sensitive user email addresses.

What is CVE-2023-5561?

The vulnerability in WordPress arises from its failure to properly restrict the user fields searchable via the REST API. This flaw enables attackers to obtain email addresses of users who have posted public content on impacted websites through an Oracle-style attack.

The Impact of CVE-2023-5561

By exploiting this vulnerability, malicious actors can uncover email addresses of users, leading to privacy breaches, unauthorized communication, and potential exposure to phishing attacks.

Technical Details of CVE-2023-5561

The following technical aspects shed light on the vulnerability:

Vulnerability Description

WordPress versions prior to 6.3.2 lack adequate restrictions on searchable user fields via the REST API, facilitating the exposure of user email addresses to unauthorized entities.

Affected Systems and Versions

Various versions of WordPress, including 6.3.0 to 4.7.0, are impacted by this security flaw, with specific versions specified as vulnerable in the CVE description.

Exploitation Mechanism

Exploiting this vulnerability allows attackers to discern the email addresses of users who have posted public content on affected WordPress websites by leveraging an Oracle-style attack.

Mitigation and Prevention

To address and prevent the exploitation of CVE-2023-5561, the following steps can be taken:

Immediate Steps to Take

Upgrade WordPress installations to version 6.3.2 or the latest release to mitigate the vulnerability.
Regularly monitor for security updates and patches from WordPress to address any known vulnerabilities promptly.

Long-Term Security Practices

Implement strong access controls and authentication mechanisms to restrict unauthorized access to sensitive user information.
Conduct regular security audits and testing to identify and address any potential vulnerabilities in WordPress installations.

Patching and Updates

WordPress users should prioritize updating their installations to version 6.3.2 or higher to ensure protection against CVE-2023-5561 and other known security weaknesses.