CVE-2017-18539 in WebLibrarian Plugin
Summary
by MITRE
The weblibrarian plugin before 3.4.8.6 for WordPress has XSS via front-end short codes.
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Analysis
by VulDB Data Team • 08/01/2020
The vulnerability identified as CVE-2017-18539 affects the weblibrarian plugin for WordPress, specifically versions prior to 3.4.8.6, and represents a cross-site scripting vulnerability that can be exploited through front-end shortcodes. This issue falls under the category of injection flaws and is classified as CWE-79, which describes improper neutralization of input during web output rendering. The vulnerability exists because the plugin fails to properly sanitize and validate user input that is processed through shortcode parameters, allowing malicious actors to inject arbitrary JavaScript code into web pages viewed by other users.
The technical flaw manifests when administrators or users with appropriate privileges create or modify content using the weblibrarian plugin's shortcode functionality. These shortcodes are designed to display library-related information on WordPress websites, but due to insufficient input validation and output escaping mechanisms, malicious payloads can be injected through shortcode attributes. When legitimate users view pages containing these compromised shortcodes, their browsers execute the injected malicious JavaScript code, potentially leading to session hijacking, credential theft, or redirection to malicious websites. The vulnerability is particularly dangerous because it operates on the front-end of the website, making it accessible to all visitors without requiring administrative privileges.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities within the context of the affected WordPress site. Attackers could leverage this vulnerability to steal cookies, modify page content, redirect users to phishing sites, or even establish persistent backdoors through more sophisticated attack vectors. The vulnerability affects the entire user base of affected WordPress installations, making it a critical security concern for any organization relying on the weblibrarian plugin. According to ATT&CK framework, this vulnerability maps to T1059.007 for scripting and T1566 for phishing, as it enables both code execution and social engineering attacks through compromised website content. The exposure period for this vulnerability was significant, as many WordPress sites remained vulnerable for extended periods due to delayed plugin updates.
Mitigation strategies for CVE-2017-18539 primarily involve immediate plugin version updates to 3.4.8.6 or later, which contain proper input sanitization and output escaping mechanisms. Organizations should implement comprehensive patch management processes to ensure all WordPress plugins remain current with security updates. Additional defensive measures include implementing Content Security Policy headers to limit script execution, conducting regular security audits of installed plugins, and monitoring website traffic for suspicious activities. Network administrators should also consider implementing web application firewalls to detect and block malicious shortcode parameters. The vulnerability highlights the importance of proper input validation and output encoding practices as outlined in OWASP Top 10 and the Secure Coding practices recommended by NIST. Regular security assessments and automated vulnerability scanning should be integrated into the organization's security posture to identify similar issues in other third-party components and plugins.