CVE-2022-27845 in PlausibleHQ Plausible Analytics Plugin
Summary
by MITRE • 04/12/2022
Authenticated (admin or higher user role) Stored Cross-Site Scripting (XSS) in PlausibleHQ Plausible Analytics (WordPress plugin)
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Analysis
by VulDB Data Team • 04/14/2022
The vulnerability CVE-2022-27845 represents a critical stored cross-site scripting flaw within the Plausible Analytics WordPress plugin, specifically affecting versions prior to 2.1.1. This security weakness resides in the plugin's handling of user input within administrative contexts, where authenticated users with admin or higher privileges can exploit the vulnerability. The flaw allows attackers to inject malicious JavaScript code that persists in the application's database and executes whenever affected pages are loaded by other users, including administrators. This type of vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting attacks where input data is not properly sanitized before being rendered back to users. The vulnerability impacts the WordPress ecosystem through the Plausible Analytics plugin, which is widely used for web analytics and tracking user behavior on websites.
The technical implementation of this stored XSS vulnerability occurs when administrators interact with the plugin's administrative interface and submit data that contains malicious script payloads. These payloads are stored in the WordPress database without proper sanitization or encoding, creating a persistent vector for attack. When other users, particularly administrators, access pages that display this stored data, the malicious JavaScript executes in their browser context, potentially enabling session hijacking, credential theft, or arbitrary code execution. The vulnerability is particularly dangerous because it requires only administrative privileges to exploit, and the stored nature means the attack persists until the malicious data is removed from the database. This aligns with ATT&CK technique T1566.001 which covers credential access through phishing with a malicious attachment or link, where the malicious payload is already present in the application's data stores.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it provides attackers with a persistent foothold within the WordPress environment. Administrators who view pages containing the stored malicious code become victims of the XSS attack, potentially compromising their sessions and enabling further exploitation of the WordPress installation. Attackers could leverage this vulnerability to escalate privileges, steal sensitive information, or redirect users to malicious domains for phishing campaigns. The persistent nature of stored XSS means that the attack vector remains active even after the initial injection, making it particularly challenging to detect and remediate. Organizations using the Plausible Analytics plugin without the proper security updates face significant risk of unauthorized access and potential data breaches. The vulnerability demonstrates the importance of proper input validation and output encoding in web applications, as outlined in OWASP Top 10 2021 category A03: Injection and A07: Identification and Authentication Failures, where inadequate sanitization of user inputs creates opportunities for attackers to execute malicious code within the victim's browser context.
Mitigation strategies for CVE-2022-27845 focus primarily on immediate patching of the Plausible Analytics plugin to version 2.1.1 or later, which includes proper input sanitization and output encoding mechanisms. Organizations should also implement additional defensive measures such as content security policy headers to limit script execution, regular monitoring of plugin updates, and administrative access controls to minimize the attack surface. Security teams should conduct thorough audits of all installed WordPress plugins to identify similar vulnerabilities and ensure proper input validation across all user-facing interfaces. The vulnerability highlights the critical importance of maintaining up-to-date security patches and implementing automated monitoring systems to detect and respond to potential exploitation attempts in real-time. Additionally, implementing web application firewalls and input validation layers can provide additional protection against similar stored XSS vulnerabilities in other applications within the organization's attack surface.