CVE-2025-23943 in PDF.js Shortcode Plugin
Summary
by MITRE • 01/16/2025
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in arul PDF.js Shortcode allows Stored XSS.This issue affects PDF.js Shortcode: from n/a through 1.0.
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Analysis
by VulDB Data Team • 02/10/2025
The CVE-2025-23943 vulnerability represents a critical cross-site scripting flaw within the PDF.js Shortcode plugin, specifically targeting versions ranging from an unknown initial state through version 1.0. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and dangerous web application security flaws. The issue manifests during the web page generation process where input data fails to be properly sanitized or neutralized before being rendered back to users, creating an environment where malicious scripts can be injected and executed within the context of other users' browsers. The stored nature of this vulnerability means that the malicious payload is persistently saved within the application's database or storage system, making it particularly dangerous as it can affect multiple users over time without requiring repeated exploitation attempts.
The technical exploitation of this vulnerability occurs when a malicious actor submits crafted input through the PDF.js Shortcode functionality, which then gets stored in the system's database without proper validation or sanitization. When other users view pages containing this stored content, the malicious script executes within their browser context, potentially leading to session hijacking, credential theft, or redirection to malicious websites. The vulnerability's impact is amplified by the fact that it operates at the web page generation layer, meaning that any content processed through the shortcode functionality could become a vector for attack. This type of vulnerability is particularly concerning in WordPress environments where plugins often handle user-generated content, as it can be leveraged to compromise entire websites and their user bases.
From an operational standpoint, this vulnerability creates significant risk for organizations relying on the PDF.js Shortcode plugin for document display functionality. The stored XSS nature means that once exploited, the malicious code can persist indefinitely until manually removed from the system, potentially allowing attackers to maintain long-term access to compromised systems. The attack surface is further expanded by the fact that this vulnerability affects the plugin's core functionality of generating web pages, meaning that legitimate users who encounter the malicious content during normal operations may unknowingly become victims. Security teams must consider that this vulnerability could be exploited to establish persistent backdoors or to conduct phishing attacks against users who trust the compromised website. The impact extends beyond individual user sessions to potentially compromise entire website infrastructures, especially in environments where the plugin is widely used or integrated with other security-critical components.
Mitigation strategies for CVE-2025-23943 should prioritize immediate remediation through plugin updates to versions that address the XSS vulnerability, as recommended by the software vendor. Organizations must implement comprehensive input validation and output encoding mechanisms to prevent malicious content from being stored or executed, following established security practices such as those outlined in the OWASP Top Ten and the MITRE ATT&CK framework for web application security. The implementation of Content Security Policy (CSP) headers can provide an additional layer of protection by restricting script execution and preventing unauthorized code from running within affected pages. Regular security auditing and monitoring of user-generated content should be implemented to detect potential exploitation attempts, while security teams should maintain awareness of the specific ATT&CK techniques related to XSS vulnerabilities, particularly those involving stored payloads. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts and provide real-time protection against known attack patterns associated with this class of vulnerability.