CVE-2019-16522 in eu-cookie-law Plugin
Summary
by MITRE
The eu-cookie-law plugin through 3.0.6 for WordPress (aka EU Cookie Law (GDPR)) is susceptible to Stored XSS due to improper encoding of several configuration options in the admin area and the displayed cookie consent message. This affects Font Color, Background Color, and the Disable Cookie text. An attacker with high privileges can attack other users.
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Analysis
by VulDB Data Team • 01/09/2024
The eu-cookie-law plugin for WordPress represents a critical security vulnerability through its improper handling of user input within the administrative configuration interface. This flaw exists in versions prior to 3.0.7 and specifically affects the plugin's ability to properly sanitize and encode configuration parameters that are later rendered in the browser. The vulnerability manifests as a stored cross-site scripting attack vector that allows malicious actors to inject persistent malicious code into the plugin's configuration settings, which then executes whenever the affected page is loaded by other users. The affected parameters include Font Color, Background Color, and Disable Cookie text fields, all of which are processed without adequate input validation or output encoding mechanisms.
The technical implementation of this vulnerability stems from the plugin's failure to properly escape user-supplied values before storing them in the WordPress database and subsequently rendering them in HTML contexts. When administrators or privileged users modify these configuration options through the WordPress admin interface, the plugin does not adequately sanitize the input data, allowing special characters and script tags to be stored directly in the database. This creates a persistent threat where any user who accesses the plugin's configuration page or views the cookie consent message on the frontend will execute the malicious code within their browser context. The vulnerability is particularly concerning because it requires only high privilege access to the WordPress admin area, which typically includes administrators, editors, or users with equivalent capabilities, making it exploitable by insider threats or compromised accounts.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with the ability to manipulate the user experience and potentially exfiltrate sensitive data from authenticated users. The stored XSS attack can be leveraged to steal cookies, session tokens, or other sensitive information from users who view the compromised pages. Additionally, attackers can use this vulnerability to redirect users to malicious websites, inject phishing content, or perform other malicious activities that exploit the trust relationship between the legitimate WordPress site and its visitors. The vulnerability affects the core functionality of the cookie consent message display, potentially undermining the plugin's intended purpose of ensuring GDPR compliance while simultaneously creating security risks for end users. This attack vector aligns with CWE-79 Cross-site Scripting flaws and can be mapped to ATT&CK technique T1566.001 for initial access through malicious content, and T1071.001 for application layer protocol usage.
Mitigation strategies for this vulnerability require immediate plugin updates to version 3.0.7 or later, where the developers have implemented proper input sanitization and output encoding mechanisms. Organizations should also implement strict input validation for all user-supplied data within administrative interfaces and ensure that all configuration parameters are properly escaped before being rendered in HTML contexts. Security monitoring should include regular scanning for outdated plugins and themes, as well as implementing Content Security Policy headers to limit the impact of potential XSS attacks. Additionally, privileged user accounts should be protected with strong authentication measures including multi-factor authentication, and access controls should be implemented to minimize the attack surface. The vulnerability demonstrates the importance of proper input/output encoding practices and highlights the critical need for security considerations in plugin development for content management systems, particularly those dealing with user-facing compliance features such as cookie consent mechanisms.