CVE-2017-2285 is a cross-site scripting (XSS) vulnerability identified in the WordPress plugin 'Simple Custom CSS and JS' developed by SilkyPress. This vulnerability affects all versions prior to 3.4. The flaw allows remote attackers to inject arbitrary web scripts or HTML code through unspecified vectors, which can be exploited when a user with appropriate privileges interacts with the maliciously crafted content. The vulnerability is classified under CWE-79, indicating improper neutralization of input during web page generation. The CVSS v3.1 base score is 6.1 (medium severity), with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requires user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability can affect resources beyond the vulnerable component. The impact affects confidentiality and integrity (C:L/I:L) but not availability (A:N). No known exploits in the wild have been reported, and no official patch links are provided in the data, though upgrading to version 3.4 or later is implied to remediate the issue. The vulnerability enables attackers to execute malicious scripts in the context of the victim’s browser, potentially leading to session hijacking, defacement, or redirection to malicious sites. Since the plugin allows custom CSS and JS injection, improper sanitization of user input is the root cause, enabling injection of executable code.

For European organizations using WordPress websites with the vulnerable 'Simple Custom CSS and JS' plugin, this vulnerability poses a risk of client-side attacks that can compromise user data confidentiality and integrity. Attackers could exploit this to steal session cookies, perform actions on behalf of users, or deliver malware. This is particularly concerning for organizations handling sensitive customer data, financial transactions, or personal information under GDPR regulations. The vulnerability could lead to reputational damage, regulatory fines, and loss of customer trust. Since the attack requires user interaction, phishing or social engineering campaigns could be used to lure users into triggering the exploit. The scope change indicates that the impact could extend beyond the plugin itself, potentially affecting other parts of the website or connected systems. Although no known exploits are reported, the medium severity and ease of exploitation without authentication make it a relevant threat. European organizations with public-facing WordPress sites using this plugin should consider this a moderate risk that requires prompt remediation to prevent exploitation.

1. Immediate upgrade of the 'Simple Custom CSS and JS' plugin to version 3.4 or later, where the vulnerability is fixed. 2. If upgrading is not immediately possible, restrict access to the plugin’s functionality to trusted administrators only, minimizing exposure. 3. Implement Content Security Policy (CSP) headers to reduce the impact of injected scripts by restricting script sources. 4. Conduct thorough input validation and sanitization on any custom CSS or JS inputs, ensuring no executable scripts can be injected. 5. Monitor website logs and user activity for unusual behavior indicative of XSS exploitation attempts. 6. Educate users and administrators about phishing and social engineering risks that could trigger user interaction-based exploits. 7. Regularly scan WordPress sites with security tools that detect XSS vulnerabilities and plugin weaknesses. 8. Backup website data and configurations regularly to enable quick recovery in case of compromise.