CVE-2024-10242: Authentication Endpoint XSS Vulnerability

CVE-2024-10242 Overview

CVE-2024-10242 is a reflected Cross-Site Scripting (XSS) vulnerability affecting WSO2 products. The authentication endpoint fails to adequately validate user-supplied input before reflecting it back in the response. This allows an attacker to inject malicious script payloads into the input parameters, which are then executed by the victim's browser.

Successful exploitation can enable an attacker to redirect the user's browser to a malicious website, modify the UI of the web page, or retrieve information from the browser. However, the impact is limited as session-related sensitive cookies are protected by the httpOnly flag, preventing session hijacking.

Critical Impact

Attackers can inject malicious scripts via the authentication endpoint to redirect users, modify page content, or exfiltrate browser-accessible information, though session cookies remain protected.

Affected Products

• WSO2 Products (specific versions not disclosed in CVE data)

Discovery Timeline

• 2026-04-16 - CVE CVE-2024-10242 published to NVD
• 2026-04-16 - Last updated in NVD database

Technical Details for CVE-2024-10242

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting (XSS). The flaw exists in the authentication endpoint where user-supplied input is reflected back in the HTTP response without proper sanitization or encoding.

When a user submits data through the authentication endpoint, the application echoes the input directly into the response HTML without neutralizing potentially dangerous characters such as <, >, ", and '. This allows attackers to craft URLs containing malicious JavaScript payloads that execute in the context of the victim's browser session.

The attack requires user interaction—specifically, the victim must click on a malicious link or be redirected to a crafted URL. The scope is changed, meaning the vulnerability in the authentication component can impact resources beyond its security scope.

Root Cause

The root cause of CVE-2024-10242 is insufficient input validation and output encoding in the WSO2 authentication endpoint. The application fails to properly sanitize user-controlled input before including it in the HTTP response. Specifically, the endpoint does not apply context-appropriate encoding (such as HTML entity encoding) when reflecting user input, allowing script content to be interpreted as executable code by the browser.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker crafts a malicious URL containing JavaScript payload within a parameter accepted by the authentication endpoint. The attacker then distributes this link through phishing emails, malicious websites, or other social engineering techniques.

When a victim clicks the link, their browser sends a request to the legitimate WSO2 authentication endpoint. The server reflects the malicious payload in the response, and the victim's browser executes the injected script in the context of the WSO2 application's origin. This enables the attacker to perform actions such as:

• Redirecting users to phishing sites
• Modifying the visible content of the authentication page
• Capturing form data entered by the user
• Accessing browser-stored information accessible to scripts

The presence of httpOnly flags on session cookies mitigates the risk of direct session token theft.

Detection Methods for CVE-2024-10242

Indicators of Compromise

• Unusual URL patterns in web server logs containing script tags or JavaScript event handlers in authentication endpoint parameters
• Web application firewall (WAF) alerts for XSS patterns targeting authentication URLs
• User reports of unexpected redirects or page modifications when accessing authentication pages
• Referrer logs showing traffic from suspicious external domains to authentication endpoints

Detection Strategies

• Deploy web application firewall rules to detect and block common XSS payloads in HTTP requests to authentication endpoints
• Implement Content Security Policy (CSP) headers with strict script-src directives and monitor for CSP violation reports
• Enable verbose logging on authentication endpoints and analyze logs for encoded script content or suspicious parameter values
• Conduct regular security assessments using automated XSS scanning tools against authentication interfaces

Monitoring Recommendations

• Monitor CSP violation reports for attempted script injections that were blocked by policy
• Track and alert on authentication endpoint requests with unusually long or encoded parameter values
• Implement real-time log analysis to detect patterns consistent with XSS probe attempts
• Configure alerts for any changes to authentication endpoint behavior or response patterns

How to Mitigate CVE-2024-10242

Immediate Actions Required

• Review the WSO2 Security Advisory WSO2-2024-3741 for vendor-specific patching guidance
• Deploy web application firewall rules to filter malicious XSS payloads targeting authentication endpoints
• Implement or strengthen Content Security Policy headers to prevent inline script execution
• Audit all authentication-related endpoints for similar input validation issues

Patch Information

WSO2 has released security patches addressing this vulnerability. Organizations running affected WSO2 products should consult the official WSO2 Security Advisory WSO2-2024-3741 for specific patch versions and upgrade instructions. Apply the latest security updates following your organization's change management procedures.

Workarounds

• Implement strict input validation on all authentication endpoint parameters, rejecting requests containing script-related content
• Deploy a web application firewall with XSS protection rules in blocking mode
• Configure Content Security Policy headers with script-src 'self' to prevent execution of inline scripts
• Use URL filtering at the network perimeter to detect and block requests with suspicious encoded payloads

# Example CSP header configuration for Apache
# Add to httpd.conf or .htaccess for authentication endpoints
Header always set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'self';"
Header always set X-XSS-Protection "1; mode=block"
Header always set X-Content-Type-Options "nosniff"