CVE-2025-39549 in Most and Least Read Posts Widget Plugin
Summary
by MITRE • 04/16/2025
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in whiletrue Most And Least Read Posts Widget allows Stored XSS. This issue affects Most And Least Read Posts Widget: from n/a through 2.5.20.
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Analysis
by VulDB Data Team • 04/16/2025
The vulnerability CVE-2025-39549 represents a critical cross-site scripting flaw in the Most And Least Read Posts Widget plugin for WordPress systems. This weakness falls under the CWE-79 category of Cross-Site Scripting, specifically manifesting as a stored XSS vulnerability that allows malicious actors to inject persistent malicious scripts into web pages viewed by other users. The affected plugin version range spans from an unspecified initial version through 2.5.20, indicating a prolonged period during which this security gap existed.
The technical flaw occurs during the web page generation process where user input provided through the widget configuration or content management interface fails to undergo proper sanitization and neutralization before being rendered in HTML output. When administrators or users interact with the widget's administrative interface and input malicious script code, this content gets stored in the database without adequate validation or encoding. Subsequently, when other users access pages containing the widget, the stored malicious scripts execute in their browsers, potentially compromising their sessions and enabling unauthorized actions.
The operational impact of this vulnerability extends beyond simple script execution, as it creates a persistent threat vector that can be exploited by attackers to hijack user sessions, steal sensitive information, manipulate content, or redirect users to malicious websites. The stored nature of this XSS vulnerability means that once the malicious payload is injected, it remains active until manually removed from the system, allowing attackers to maintain long-term access to affected environments. This vulnerability particularly affects WordPress installations where the widget plugin is actively used, potentially compromising entire sites if administrators have elevated privileges.
Security professionals should consider this vulnerability in the context of the ATT&CK framework under the T1566.001 technique for Initial Access through Web Application Attacks, where XSS serves as a primary vector for establishing footholds in web applications. The vulnerability demonstrates poor input validation practices that align with ATT&CK technique T1211 for Exploitation for Privilege Escalation. Organizations should implement immediate mitigations including plugin updates to versions beyond 2.5.20, input validation and output encoding measures, and comprehensive security audits of all installed plugins. Additionally, implementing Content Security Policy headers and regular security scanning of web applications can help detect and prevent exploitation attempts. The vulnerability highlights the critical importance of maintaining up-to-date software components and implementing robust input sanitization mechanisms as recommended by OWASP Top Ten security practices.