Overview
The cybersecurity landscape is riddled with innumerable threats and vulnerabilities, one of which is the CVE-2025-3605. This vulnerability exists within the Frontend Login and Registration Blocks plugin for WordPress, affecting all versions up to and including 1.0.7. The flaw can lead to privilege escalation via an account takeover, which can have severe consequences for the integrity and security of a system. It is a severe issue, particularly for websites powered by WordPress, which is one of the most widely used website management systems globally.
The impact of this vulnerability is elevated due to the possibility of unauthenticated attackers changing arbitrary user email addresses. This flaw could allow an attacker to reset user passwords, including administrators’, thereby gaining unauthorized access to their accounts, potentially leading to system compromise or data leakage.
Vulnerability Summary
CVE ID: CVE-2025-3605
Severity: Critical (CVSS: 9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise, data leakage
Affected Products
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Product | Affected Versions
Frontend Login and Registration Blocks Plugin for WordPress | Up to and including 1.0.7
How the Exploit Works
The vulnerability is due to insufficient validation of a user’s identity prior to updating their details such as email addresses. The flaw lies in the function flr_blocks_user_settings_handle_ajax_callback(), which does not properly validate a user’s identity. This allows an unauthenticated attacker to send a malicious request to this function and change arbitrary user’s email addresses, including those of administrators.
The attacker can then use the updated email address to reset the user’s password, thereby gaining unauthorized access to their account. This can lead to system compromise or data leakage if the account belongs to an administrator or contains sensitive information.
Conceptual Example Code
The following conceptual example demonstrates how the vulnerability might be exploited:
POST /wp-admin/admin-ajax.php HTTP/1.1
Host: target.example.com
Content-Type: application/json
{
"action": "flr_blocks_user_settings_handle_ajax_callback",
"user_id": "1",
"user_email": "attacker@example.com"
}In the above example, the attacker sends a POST request to the ‘admin-ajax.php’ endpoint with the action set to ‘flr_blocks_user_settings_handle_ajax_callback’, the user_id set to ‘1’ (which typically represents the administrator), and the user_email changed to the attacker’s email.
Mitigation
To mitigate the CVE-2025-3605 vulnerability, users are advised to apply the vendor patch as soon as it becomes available. Until then, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure to block any malicious requests attempting to exploit this vulnerability.