CVE-2022-3852: VR Calendar WordPress Plugin Vulnerability - Cross-Site Request Forgery Exploit in Versions Up To and Including 2.3.3

The VR Calendar plugin for WordPress enables users to create and manage reservation and booking calendars for their websites. However, it has come to light that this widely used plugin is prone to a security vulnerability in versions up to, and including, 2.3.3. The vulnerability, titled CVE-2022-3852, exposes the plugin to Cross-Site Request Forgery (CSRF) attacks due to inadequate nonce validation.

In this post, we will discuss the details of the exploit, provide code snippets showcasing the vulnerability, and include links to relevant resources and references for further understanding and mitigation.

Exploit Details

The VR Calendar plugin suffers from missing or incorrect nonce validation in several functions. Nonce validation is a crucial security feature commonly used in WordPress plugins to verify the origin and intent of a request. Without proper validation, attackers can gain the ability to delete, modify calendars, and tamper with plugin settings via malformed requests.

In order to exploit this vulnerability successfully, an attacker needs to trick a site administrator into performing an action like clicking on a maliciously crafted link. Once the administrator inadvertently executes the attacker's command, the attacker gains unauthorized access to modify or delete the targeted calendar data or plugin settings.

Code Snippet

The code snippet below demonstrates the CSRF vulnerability in the VR Calendar plugin's "saveSettings" function:

function saveSettings() {
	global $wpdb;

// Missing nonce verification here!
	if( isset( $_POST['apiKey'] ) ) {
		update_option( 'vrc_tp_api_key', sanitize_text_field( $_POST['apiKey'] ) );
	}
...
}

As seen in the snippet above, the "saveSettings" function lacks the necessary nonce validation, leaving the plugin open to CSRF attacks.

To learn more about nonce validation and safeguarding your plugins, refer to the following resources

1. WordPress Nonces Documentation
2. WordPress Plugin Handbook: Security

If you have the VR Calendar plugin installed on your WordPress website, it is crucial to

1. Update the plugin to the latest version (version 2.3.4 or higher), which addresses the CSRF vulnerability.

Make sure your environment is secured and follow best practices in WordPress security.

In summary, CVE-2022-3852 represents a significant threat to WordPress websites using the VR Calendar plugin. It is essential to be aware of this vulnerability and take immediate steps to mitigate the risks associated with it. By updating the plugin to its latest version and following security best practices, you can safeguard your website from CSRF attacks and maintain a secure online presence.

Remember always to keep your WordPress plugins and themes up-to-date and adhere to security recommendations by the WordPress community and experts to ensure a safe and secure website experience.

Timeline

Published on: 11/03/2022 18:15:00 UTC
Last modified on: 11/04/2022 15:48:00 UTC