CVE-2021-24923 : Security Advisory and Response

A detailed analysis of the CVE-2021-24923 vulnerability affecting the Newsletter, SMTP, Email marketing, and Subscribe forms by Sendinblue WordPress plugin.

Understanding CVE-2021-24923

This CVE involves a security issue in the Sendinblue WordPress plugin version prior to 3.1.25, leading to a Reflected Cross-Site Scripting (XSS) vulnerability.

What is CVE-2021-24923?

The vulnerability arises due to improper handling of the sib-statistics-date parameter, resulting in a Reflected Cross-Site Scripting issue. Attackers can exploit this to execute malicious scripts in the context of a user's browser.

The Impact of CVE-2021-24923

The impact of this vulnerability can allow attackers to inject unauthorized scripts into web pages viewed by other users, potentially leading to phishing attacks, data theft, or unauthorized actions on behalf of legitimate users.

Technical Details of CVE-2021-24923

This section covers the specifics of the vulnerability.

Vulnerability Description

The vulnerability in the Sendinblue WordPress plugin version < 3.1.25 allows attackers to execute arbitrary scripts in the browser of a user visiting a malicious page.

Affected Systems and Versions

The vulnerability affects versions of the Sendinblue WordPress plugin before version 3.1.25.

Exploitation Mechanism

Exploiting this issue involves crafting a malicious link or content that includes the vulnerable sib-statistics-date parameter to trigger the XSS payload.

Mitigation and Prevention

Protecting systems from CVE-2021-24923 requires immediate actions and long-term security practices.

Immediate Steps to Take

We recommend updating the Sendinblue WordPress plugin to version 3.1.25 or above to mitigate this vulnerability. Additionally, users should be cautious about clicking on untrusted links or visiting suspicious websites.

Long-Term Security Practices

Implementing input validation, output encoding, and proper escaping mechanisms in web applications can help prevent XSS vulnerabilities. Regular security audits and monitoring for emerging threats are also essential.

Patching and Updates

Keep systems and software up to date with the latest security patches and fixes to address known vulnerabilities and improve overall security posture.