Understanding the Authenticated XSS in Mailchimp for WordPress (MC4WP) Plugin
A security flaw, identified as CVE-2021-36833, has been found in the Mailchimp for WordPress (MC4WP) plugin, a popular tool for connecting WordPress websites with Mailchimp email marketing services. This vulnerability is an Authenticated Stored Cross-Site Scripting (XSS) issue, meaning it allows an attacker to inject harmful scripts into the website. However, exploiting this particular flaw requires an administrator or a user with a higher role to be logged in and perform a specific action, which reduces its immediate danger.
Cross-Site Scripting (XSS) attacks happen when malicious code, often in the form of browser-side scripts, is injected into legitimate and trusted websites. When other users visit the affected page, their browsers execute these malicious scripts, which can then steal sensitive information, redirect them to harmful sites, or deface the website.
CVE Details
- Product: Mailchimp for WordPress (MC4WP) plugin for WordPress
- Published Date: May 20, 2022
- Severity: Medium
- Status: Analyzed
Affected Products
The Authenticated Stored Cross-Site Scripting (XSS) vulnerability affects the ibericode Mailchimp for WordPress (MC4WP) plugin for WordPress versions up to and including 4.8.6. If you are using any version equal to or older than 4.8.6, your website may be at risk.
Current Status
This vulnerability has been officially analyzed. This means that security researchers and vendors have reviewed the flaw, understood its nature, and typically, solutions or mitigations have been developed and released.
Severity Level
CVE-2021-36833 has been assigned a CVSS score of 4.8, classifying it as a Medium severity vulnerability. While XSS vulnerabilities can be quite dangerous, the “authenticated” nature of this specific flaw means an attacker would first need to gain access to an administrator-level account or higher on your WordPress site to exploit it. This significantly raises the bar for exploitation compared to vulnerabilities that can be triggered by unauthenticated users.
Possible Solutions
The good news is that a fix is available for this vulnerability. To secure your WordPress website and protect against this specific XSS flaw in the Mailchimp for WordPress plugin, you should:
- Update to Version 4.8.7 or Later: The most effective solution is to update your Mailchimp for WordPress (MC4WP) plugin to version 4.8.7 or any subsequent version. These updated versions contain the necessary patches to close this security loophole.
Regularly updating your WordPress plugins and themes is a fundamental cybersecurity practice. It ensures you benefit from the latest security fixes and performance improvements.
References
https://patchstack.com/database/vulnerability/mailchimp-for-wp/wordpress-mc4wp-plugin-4-8-6-authenticated-stored-cross-site-scripting-xss-vulnerability
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-36833
