EUVD-2025-22769

Comprehensive Technical Analysis of EUVD-2025-22769

1. Vulnerability Assessment and Severity Evaluation

The vulnerability in the Melapress Login Security plugin for WordPress, identified as EUVD-2025-22769 (CVE-2025-6895), is classified as an Authentication Bypass due to missing authorization within the get_valid_user_based_on_token() function. This vulnerability affects versions 2.1.0 to 2.1.1 of the plugin. The CVSS (Common Vulnerability Scoring System) base score of 9.8 indicates a critical severity level. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H breaks down as follows:

• AV:N (Network): The vulnerability is exploitable over the network.
• AC:L (Low): The attack complexity is low.
• PR:N (None): No privileges are required to exploit the vulnerability.
• UI:N (None): No user interaction is required.
• S:U (Unchanged): The scope of the vulnerability is unchanged.
• C:H (High): Confidentiality impact is high.
• I:H (High): Integrity impact is high.
• A:H (High): Availability impact is high.

This high severity score underscores the critical nature of the vulnerability, which can lead to unauthorized access to user accounts.

2. Potential Attack Vectors and Exploitation Methods

The primary attack vector involves unauthenticated attackers exploiting the missing authorization check in the get_valid_user_based_on_token() function. By knowing an arbitrary user meta value, an attacker can bypass authentication checks and log in as that user. This can be achieved through:

• Brute Force Attacks: Attackers may attempt to guess user meta values through brute force methods.
• Social Engineering: Attackers may use social engineering techniques to obtain user meta values.
• Exploiting Other Vulnerabilities: Attackers may exploit other vulnerabilities in the system to gain access to user meta values.

3. Affected Systems and Software Versions

The vulnerability affects WordPress sites using the Melapress Login Security plugin versions 2.1.0 to 2.1.1. Any WordPress installation with this plugin within the specified version range is at risk.

4. Recommended Mitigation Strategies

To mitigate the risk associated with this vulnerability, the following steps are recommended:

• Update the Plugin: Immediately update the Melapress Login Security plugin to a version higher than 2.1.1, if available.
• Disable the Plugin: If an update is not available, consider disabling the plugin until a patched version is released.
• Implement Additional Security Measures: Use multi-factor authentication (MFA) and monitor for unusual login activities.
• Regular Audits: Conduct regular security audits and vulnerability assessments to identify and mitigate similar issues.
• User Education: Educate users about the risks of sharing sensitive information and the importance of strong, unique passwords.

5. Impact on European Cybersecurity Landscape

The vulnerability poses a significant risk to the European cybersecurity landscape, particularly for organizations and individuals using WordPress with the affected plugin. Unauthorized access to user accounts can lead to data breaches, financial loss, and reputational damage. Given the widespread use of WordPress, the impact could be extensive, affecting various sectors including e-commerce, media, and government websites.

6. Technical Details for Security Professionals

Vulnerable Function:

• get_valid_user_based_on_token() in class-melapress-login-security.php and class-temporary-logins.php.

Exploitation Steps:

1. Identify the user meta value required for authentication.
2. Craft a request that includes this meta value.
3. Bypass the authentication check by exploiting the missing authorization in the get_valid_user_based_on_token() function.

Code Review:

• Review the get_valid_user_based_on_token() function for missing authorization checks.
• Ensure that all authentication functions properly validate user credentials and permissions.

Detection:

• Monitor for unusual login attempts and failed authentication logs.
• Implement intrusion detection systems (IDS) to detect and alert on suspicious activities.

Response:

• In case of a detected exploit, immediately disable the plugin and investigate the extent of the breach.
• Notify affected users and take steps to secure their accounts.

References:

• Wordfence Threat Intelligence
• WordPress Plugin Page
• Plugin Source Code
• Temporary Logins Module
• Changeset

By addressing this vulnerability promptly and comprehensively, organizations can significantly reduce the risk of unauthorized access and potential data breaches.