CVE-2023-6923 in Matomo Plugin
Summary
by MITRE • 02/29/2024
The Matomo Analytics – Ethical Stats. Powerful Insights. plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the idsite parameter in all versions up to, and including, 4.15.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 04/12/2026
The vulnerability identified as CVE-2023-6923 affects the Matomo Analytics plugin for WordPress, specifically targeting versions up to and including 4.15.3. This plugin serves as a powerful analytics solution that helps website owners track user behavior and gather insights about their audience. The issue stems from a reflected cross-site scripting flaw that occurs when the plugin processes the idsite parameter without adequate input validation or output sanitization. The vulnerability exists within the plugin's handling of user-supplied data, creating an attack surface that can be exploited by malicious actors to inject malicious scripts into web pages that are subsequently executed by unsuspecting users.
The technical flaw manifests in the plugin's insufficient input sanitization mechanisms and lack of proper output escaping for the idsite parameter. When a user visits a page that includes this parameter in the URL, the plugin fails to adequately validate or escape the input before rendering it in the HTML output. This creates a classic reflected XSS vulnerability where an attacker can craft a malicious URL containing script payloads that get executed when a victim clicks on the link. The vulnerability is particularly concerning because it affects an unauthenticated attack vector, meaning that no user credentials or administrative privileges are required to exploit the flaw. According to CWE standards, this represents a CWE-79: Cross-site Scripting vulnerability, specifically categorized as reflected XSS due to the nature of the attack where malicious scripts are reflected off the web server to the victim's browser.
The operational impact of this vulnerability extends beyond simple script injection, as it can potentially enable more sophisticated attacks within the context of the compromised WordPress site. An attacker could leverage this vulnerability to steal session cookies, redirect users to malicious sites, perform actions on behalf of authenticated users, or even escalate privileges if the victim has administrative access to the WordPress installation. The reflected nature of the attack means that the malicious payload is delivered through a URL that appears legitimate to users, making social engineering attacks more effective. This vulnerability aligns with ATT&CK technique T1566.001: Phishing: Spearphishing Attachment, where attackers can craft malicious links that exploit the XSS vulnerability to execute code in the victim's browser context. The attack requires minimal user interaction, typically involving a simple click on a crafted link, which makes it particularly dangerous in phishing campaigns targeting WordPress administrators or content creators who might be more likely to click on seemingly legitimate URLs.
Mitigation strategies for CVE-2023-6923 should prioritize immediate plugin updates to versions that address the input sanitization and output escaping deficiencies. Administrators should ensure that the Matomo Analytics plugin is updated to the latest available version that contains the necessary security patches. Additionally, implementing proper input validation mechanisms and output escaping for all user-supplied parameters can prevent similar vulnerabilities from occurring in the future. Network monitoring should be enhanced to detect suspicious URL patterns that might indicate attempts to exploit this vulnerability, and security headers such as Content Security Policy should be properly configured to limit the execution of unauthorized scripts. Regular security audits of WordPress plugins and themes are essential to identify and remediate similar vulnerabilities, as this type of flaw represents a common attack vector in web application security that requires consistent vigilance and proactive patch management strategies.