Overview
CVE-2025-59113 describes a security vulnerability in Windu CMS related to weak client-side brute-force protection. Specifically, the CMS relies on the loginError parameter to implement brute-force protection, but it does not store attempt counts or timeout information on the server. This allows an attacker to easily bypass the protection mechanism.
This vulnerability was reported and assigned CVE-2025-59113 on November 18, 2025. It’s important to note that while version 4.1 was tested and confirmed as vulnerable, other versions have not been assessed and may also be susceptible to the same issue.
The vendor, Windu, was notified about this vulnerability but has not yet provided details on the vulnerable version range or a fix.
Technical Details
Windu CMS implements a client-side brute-force protection mechanism using the loginError parameter. The CMS likely increments this parameter after each failed login attempt, and may eventually display a message or delay further login attempts based on its value. However, because the attempt count or timeout information is stored only on the client-side and not validated server-side, an attacker can bypass this protection simply by resetting the loginError parameter (e.g., by clearing cookies or manipulating the request). This essentially restarts the login attempt counter, allowing the attacker to continue attempting login without being blocked.
Example Scenario:
- Attacker submits a failed login attempt.
- Windu CMS increments the
loginErrorparameter (client-side). - Attacker intercepts the request and resets the
loginErrorparameter to its initial value or removes it entirely. - Attacker submits another failed login attempt. The client-side counter restarts, effectively bypassing the brute-force protection.
CVSS Analysis
A CVSS score has not been assigned to CVE-2025-59113 at this time. The severity is currently listed as N/A, pending further analysis and potential vendor response. However, the lack of server-side validation in the brute-force protection significantly lowers the security posture, making successful brute-force attacks substantially easier.
Possible Impact
The vulnerability could lead to the following potential impacts:
- Account Takeover: Attackers could brute-force user credentials and gain unauthorized access to user accounts.
- Data Breach: If an attacker gains access to an administrative account, they could potentially access sensitive data stored within the CMS.
- Website Defacement: An attacker with administrative privileges could modify the website content or deface the site.
- Malware Distribution: A compromised account could be used to inject malicious code into the website, potentially distributing malware to visitors.
Mitigation or Patch Steps
Since the vendor hasn’t released a patch or provided specific mitigation steps, the following actions are recommended:
- Implement Server-Side Brute-Force Protection: A proper brute-force protection mechanism should be implemented on the server-side, tracking failed login attempts and enforcing rate limiting independently of client-side information.
- Enforce Strong Password Policies: Encourage users to create strong, unique passwords to make brute-force attacks more difficult.
- Two-Factor Authentication (2FA): Enable 2FA for all user accounts to add an extra layer of security, even if the password is compromised.
- Web Application Firewall (WAF): Deploy a WAF to detect and block malicious login attempts.
- Monitor Login Attempts: Regularly monitor login attempts for suspicious activity.
If possible, consider migrating to a more secure CMS platform.
