CVE-2025-40697 Overview
A Reflected Cross-Site Scripting (XSS) vulnerability has been identified in Lewe WebMeasure affecting the /index.php endpoint. This vulnerability allows remote attackers to execute arbitrary JavaScript code through the page parameter. When successfully exploited, attackers can steal sensitive user data such as session cookies or perform actions on behalf of authenticated users.
Critical Impact
This XSS vulnerability enables attackers to hijack user sessions, steal credentials, and perform unauthorized actions by injecting malicious scripts through the vulnerable page parameter.
Affected Products
- Lewe WebMeasure (all versions prior to patch)
Discovery Timeline
- 2026-02-19 - CVE-2025-40697 published to NVD
- 2026-02-19 - Last updated in NVD database
Technical Details for CVE-2025-40697
Vulnerability Analysis
This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting. The application fails to properly sanitize user-supplied input in the page parameter before reflecting it back in the HTTP response. This allows attackers to craft malicious URLs containing JavaScript payloads that execute in the context of the victim's browser session when clicked.
The reflected nature of this XSS vulnerability means the malicious payload is not stored on the server but rather delivered through a specially crafted URL. Successful exploitation typically requires social engineering to convince a victim to click on a malicious link.
Root Cause
The root cause of this vulnerability lies in insufficient input validation and output encoding in the /index.php file. The page parameter accepts user-controlled input that is reflected in the HTTP response without proper sanitization. The application fails to implement appropriate encoding mechanisms such as HTML entity encoding or Content Security Policy headers that would prevent script execution.
Attack Vector
This vulnerability is exploitable over the network and requires user interaction. An attacker would craft a malicious URL containing JavaScript code in the page parameter and distribute it to potential victims through phishing emails, social media, or other communication channels. When a victim clicks the link while authenticated to the application, the malicious script executes in their browser context, potentially allowing the attacker to:
- Steal session cookies and authentication tokens
- Capture keystrokes and form data
- Modify page content to conduct phishing attacks
- Redirect users to malicious websites
- Perform actions on behalf of the authenticated user
The attack typically involves constructing a URL such as:
https://[target]/index.php?page=<script>malicious_code</script>
For detailed technical information about this vulnerability, refer to the INCIBE Security Notice on XSS.
Detection Methods for CVE-2025-40697
Indicators of Compromise
- HTTP requests to /index.php containing script tags or JavaScript event handlers in the page parameter
- Unusual URL patterns with encoded JavaScript payloads (e.g., %3Cscript%3E, javascript:, onerror=)
- Web application logs showing requests with suspicious parameter values containing HTML/JavaScript syntax
- Browser-based alerts or unexpected redirections reported by users after clicking links
Detection Strategies
- Implement Web Application Firewall (WAF) rules to detect and block requests containing XSS payloads in URL parameters
- Deploy network intrusion detection signatures to identify common XSS attack patterns in HTTP traffic
- Enable verbose logging on web servers to capture full request URIs for forensic analysis
- Utilize browser security features and Content Security Policy violations as detection indicators
Monitoring Recommendations
- Monitor web server access logs for requests to /index.php with unusual or encoded characters in query parameters
- Set up alerts for patterns matching known XSS payloads such as <script>, javascript:, onload=, and similar constructs
- Implement user behavior analytics to detect sessions that may have been compromised through XSS attacks
- Review Content Security Policy violation reports if CSP is deployed
How to Mitigate CVE-2025-40697
Immediate Actions Required
- Review and patch the Lewe WebMeasure installation by applying vendor-provided security updates
- Implement input validation to sanitize the page parameter and reject requests containing script tags or event handlers
- Deploy Content Security Policy (CSP) headers to restrict script execution sources
- Enable HTTPOnly and Secure flags on session cookies to prevent JavaScript access
Patch Information
Consult the INCIBE Security Notice on XSS for official vendor patch information and remediation guidance. Organizations should prioritize applying security updates as they become available from Lewe.
Workarounds
- Implement a Web Application Firewall (WAF) with XSS protection rules to filter malicious requests before they reach the application
- Apply input validation at the application layer using allowlists for the page parameter values
- Deploy Content Security Policy headers with script-src 'self' directive to prevent inline script execution
- Restrict access to the vulnerable endpoint through network segmentation or IP-based access controls until a patch is available
# Example Apache configuration for CSP headers
# Add to .htaccess or virtual host configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'"
Header set X-XSS-Protection "1; mode=block"
Header set X-Content-Type-Options "nosniff"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
