CVE-2014-3921 in popup
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in popup.php in the Simple Popup Images plugin for WordPress allows remote attackers to inject arbitrary web script or HTML via the z parameter.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/16/2024
The CVE-2014-3921 vulnerability represents a critical cross-site scripting flaw within the Simple Popup Images WordPress plugin, specifically affecting the popup.php script. This vulnerability arises from inadequate input validation and output escaping mechanisms that fail to properly sanitize user-supplied data before rendering it within web pages. The issue manifests when the z parameter is processed without sufficient sanitization, creating an avenue for malicious actors to inject arbitrary web scripts or HTML content that executes in the context of other users' browsers.
The technical exploitation of this vulnerability occurs through the manipulation of the z parameter in the popup.php endpoint, which serves as a critical attack vector for remote code execution and session hijacking. When a victim visits a compromised WordPress site or page that triggers the vulnerable plugin functionality, the malicious script injected through the z parameter executes within their browser session, potentially leading to unauthorized access to user accounts, data theft, or further exploitation of the compromised environment. This flaw directly aligns with CWE-79, which categorizes cross-site scripting vulnerabilities as a fundamental weakness in input validation and output encoding mechanisms.
The operational impact of this vulnerability extends beyond simple script injection, as it enables attackers to perform sophisticated social engineering attacks and maintain persistent access to vulnerable WordPress installations. Attackers can craft malicious payloads that steal cookies, redirect users to phishing sites, or execute additional malicious scripts that compromise the entire user session. The vulnerability's presence in a widely-used WordPress plugin amplifies its potential impact, as it affects numerous websites that rely on the Simple Popup Images functionality. This type of vulnerability is particularly dangerous in the context of the ATT&CK framework's initial access and execution phases, where adversaries establish footholds and execute malicious code within target environments.
Mitigation strategies for CVE-2014-3921 require immediate patching of the Simple Popup Images plugin to version 1.2.2 or later, which addresses the input validation issues through proper sanitization of the z parameter. Additionally, administrators should implement input validation mechanisms at the web application firewall level, enforce strict output encoding practices, and conduct regular security audits of installed WordPress plugins. The vulnerability demonstrates the importance of maintaining up-to-date software components and implementing defense-in-depth strategies that include monitoring for suspicious parameter usage and implementing content security policies to prevent unauthorized script execution. Organizations should also consider implementing automated patch management systems to ensure timely remediation of known vulnerabilities.