Ultimate Member Vulnerability – Unauthenticated Stored Cross-Site Scripting – CVE-2024-2123 |WordPress Plugin Vulnerability Report

Plugin Name: Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin

Key Information:

  • Software Type: Plugin
  • Software Slug: ultimate-member
  • Software Status: Active
  • Software Author: ultimatemember
  • Software Downloads: 9,871,019
  • Active Installs: 200,000
  • Last Updated: March 12, 2024
  • Patched Versions: 2.8.4
  • Affected Versions: <= 2.8.3

Vulnerability Details:

  • Name: Ultimate Member <= 2.8.3 - Unauthenticated Stored Cross-Site Scripting
  • Title: Security Flaw in Ultimate Member Plugin
  • Type: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
  • CVE: CVE-2024-2123
  • CVSS Score: 7.2
  • Publicly Published: March 8, 2024
  • Researcher: stealthcopter
  • Description: A critical vulnerability has been identified in the Ultimate Member plugin, affecting versions up to 2.8.3. This flaw allows for Stored Cross-Site Scripting (XSS) through various parameters due to the lack of adequate input sanitization and output escaping, enabling unauthenticated attackers to inject and execute arbitrary scripts.


The Ultimate Member plugin, an essential tool for WordPress sites in managing user profiles, registrations, logins, and memberships, has been compromised up to version 2.8.3. The discovered vulnerability opens up the possibility for unauthenticated Stored Cross-Site Scripting (XSS) attacks, posing significant risks to both website security and user privacy. The developers have promptly addressed this issue in the updated version 2.8.4, restoring the plugin's security integrity.

Detailed Overview:

Discovered by the cybersecurity researcher stealthcopter, CVE-2024-2123 underscores the paramount importance of robust security measures in plugin development, especially in those handling sensitive user data. The vulnerability's potential to be exploited by unauthenticated attackers elevates the risk, highlighting the need for immediate remedial action by site administrators to secure their platforms against unauthorized script executions and data breaches.

Advice for Users:

  • Immediate Action: It is imperative for users of the Ultimate Member plugin to update to the latest version, 2.8.4, immediately. This update rectifies the XSS vulnerability, ensuring the security of your WordPress site.
  • Check for Signs of Vulnerability: Administrators should diligently monitor their sites for indications of exploitation, such as unexpected script executions or alterations in user profiles.
  • Alternate Plugins: While the vulnerability has been rectified, users may explore alternative plugins that offer similar functionalities but might align more closely with their specific security and feature requirements.
  • Stay Updated: Regular updates of all WordPress components, including plugins, themes, and the core system, are crucial for safeguarding against known vulnerabilities and optimizing site functionality.


The swift identification and resolution of CVE-2024-2123 within the Ultimate Member plugin serve as a critical reminder of the constant vigilance required in the digital domain. For WordPress site administrators, particularly those managing small business websites with constrained technical resources, recognizing the significance of timely plugin updates is crucial for maintaining a secure and trustworthy online presence. Ensuring the use of up-to-date, secure plugins is foundational to protecting digital assets and maintaining user trust in an increasingly complex cyber environment.



In the dynamic digital ecosystem where WordPress reigns supreme for website creation and management, plugins play a pivotal role in extending functionality and enhancing user experience. Among these, the Ultimate Member plugin stands out for its comprehensive features that streamline user profile management, registration, login, and membership functionalities. Yet, the recent discovery of a vulnerability, CVE-2024-2123, in versions up to 2.8.3 has cast a spotlight on the ever-present balance between functionality and security, underscoring the imperative for constant vigilance and timely updates.

Vulnerability Insights:

CVE-2024-2123, identified by cybersecurity researcher stealthcopter, is an Unauthenticated Stored Cross-Site Scripting (XSS) vulnerability that exploits insufficient input sanitization and output escaping in the plugin. This flaw enables attackers to inject and execute malicious scripts through various parameters, posing significant threats to website security and user privacy.

Potential Risks:

The repercussions of CVE-2024-2123 extend beyond mere technical glitches, potentially leading to unauthorized access, data breaches, and a tarnished reputation for websites utilizing vulnerable versions of Ultimate Member. The unauthenticated nature of this vulnerability amplifies the risk, allowing attackers to exploit the flaw without needing login credentials.

Remedial Measures:

In response to CVE-2024-2123, the plugin's developers have released version 2.8.4, which addresses and rectifies the vulnerability. Users are urged to update their installations immediately to safeguard against potential exploits.

Historical Context:

This isn't the first time vulnerabilities have been discovered in Ultimate Member, with 53 previous instances since March 10, 2015. Each has been a learning opportunity, contributing to the plugin's evolving security landscape.

The Criticality of Timely Updates:

For small business owners and website administrators, particularly those with limited technical resources, the discovery of CVE-2024-2123 in the Ultimate Member plugin serves as a stark reminder of the critical importance of maintaining up-to-date installations. In the vast, interconnected world of WordPress, where plugins like Ultimate Member play crucial roles, the responsibility of safeguarding digital assets against emerging threats is paramount. Timely updates, coupled with a proactive approach to website security, are essential components in this ongoing battle, ensuring the integrity and trustworthiness of online platforms in an increasingly complex cybersecurity environment.


The swift resolution of CVE-2024-2123 reflects the commitment of the WordPress community and plugin developers to user security. However, it also highlights the continuous need for vigilance among website administrators. Staying informed about the latest vulnerabilities and updates is not just a best practice but a fundamental aspect of responsible website management. For small business owners navigating the digital landscape, this diligence is indispensable in protecting their online presence and the privacy of their users.

Staying Secure

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Ultimate Member Vulnerability – Unauthenticated Stored Cross-Site Scripting – CVE-2024-2123 |WordPress Plugin Vulnerability Report FAQs

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