CVE-2021-29504 : Exploit Details and Defense Strategies

WP-CLI is a command-line interface for WordPress. A vulnerability in versions prior to 2.5.0 could allow remote attackers to disable certificate verification, potentially leading to malicious updates.

Understanding CVE-2021-29504

This CVE pertains to an improper certificate validation vulnerability in the WP-CLI framework.

What is CVE-2021-29504?

The vulnerability in WP-CLI versions before 2.5.0 allows attackers to disable certificate verification, gaining control over communication and enabling the delivery of malicious updates.

The Impact of CVE-2021-29504

With a CVSS base score of 9.1 (Critical), the vulnerability could lead to high confidentiality and integrity impacts without any user interaction.

Technical Details of CVE-2021-29504

In WP-CLI versions < 2.5.0, the default behavior of

WP_CLI\Utils\http_request()

resulted in improper error handling in HTTPS requests, enabling attackers to intercept communication and push malicious updates.

Vulnerability Description

The vulnerability allows attackers to disable certificate validation, potentially leading to the delivery of harmful updates.

Affected Systems and Versions

WP-CLI versions prior to 2.5.0 are affected by this vulnerability.

Exploitation Mechanism

Attackers could intercept communication to disable certificate verification, gaining control over communication and potentially delivering malicious updates.

Mitigation and Prevention

To address CVE-2021-29504:

Immediate Steps to Take

Ensure WP-CLI is updated to version 2.5.0 or later to mitigate the vulnerability.

Long-Term Security Practices

Regularly update WP-CLI and implement secure coding practices to prevent future vulnerabilities.

Patching and Updates

Apply necessary patches and updates to maintain a secure WP-CLI environment.