CVE-2025-56605: Event Management System XSS Vulnerability

CVE-2025-56605 Overview

A reflected Cross-Site Scripting (XSS) vulnerability exists in the register.php backend script of PuneethReddyHC Event Management System 1.0. The mobile POST parameter is improperly validated and echoed back in the HTTP response without sanitization, allowing an attacker to inject and execute arbitrary JavaScript code in the victim's browser.

Critical Impact

Attackers can inject malicious JavaScript code through the mobile parameter, potentially enabling session hijacking, credential theft, or phishing attacks against users of the Event Management System.

Affected Products

• PuneethReddyHC Event Management System 1.0

Discovery Timeline

• 2026-02-26 - CVE CVE-2025-56605 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2025-56605

Vulnerability Analysis

This reflected XSS vulnerability occurs in the user registration functionality of the Event Management System. The register.php script fails to properly sanitize user-supplied input before reflecting it back to the browser, creating an injection point for malicious scripts.

The vulnerability is accessible over the network and requires some user interaction (such as clicking a crafted link). When exploited, an attacker can execute arbitrary JavaScript within the context of the victim's browser session. This can lead to unauthorized access to session cookies, manipulation of page content, or redirection to malicious sites.

The CWE-79 classification confirms this as an Improper Neutralization of Input During Web Page Generation vulnerability, a common web application security flaw that arises from insufficient input validation and output encoding.

Root Cause

The root cause is the lack of input sanitization and output encoding in the register.php script. When the mobile POST parameter is submitted, the application directly echoes the value back into the HTTP response without applying any security controls such as HTML entity encoding or input validation. This allows specially crafted input containing JavaScript to be interpreted and executed by the victim's browser.

Attack Vector

The attack vector is network-based, requiring an attacker to craft a malicious HTTP POST request targeting the register.php endpoint. The attacker must then convince a victim to submit or interact with this crafted request, typically through social engineering techniques such as phishing emails or malicious links embedded in other web pages.

When the victim's browser processes the response containing the reflected JavaScript payload, the malicious script executes with the permissions of the vulnerable application's origin, enabling various attack scenarios including cookie theft, session hijacking, and defacement.

Technical details and proof-of-concept information are available in the GitHub PoC Repository.

Detection Methods for CVE-2025-56605

Indicators of Compromise

• Unusual or malformed POST requests to register.php containing JavaScript syntax or HTML tags in the mobile parameter
• Web application logs showing requests with encoded or obfuscated script content in form submissions
• Reports of unexpected browser behavior or pop-ups when users interact with registration forms

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect XSS patterns in POST parameters, specifically targeting the mobile field
• Configure intrusion detection systems to alert on common XSS payloads such as <script>, javascript:, and event handlers like onerror or onload
• Enable detailed logging for the register.php endpoint to capture and analyze suspicious input patterns

Monitoring Recommendations

• Monitor web server access logs for anomalous registration attempts with unusual characters in form fields
• Set up alerts for multiple failed or suspicious registration requests from the same IP address
• Review Content Security Policy (CSP) violation reports if implemented, as XSS attempts may trigger CSP blocks

How to Mitigate CVE-2025-56605

Immediate Actions Required

• Apply input validation to the mobile parameter in register.php to allow only numeric characters or expected phone number formats
• Implement output encoding (HTML entity encoding) for all user-supplied data before reflecting it in HTTP responses
• Consider disabling or restricting access to the affected registration functionality until a patch is applied

Patch Information

No official vendor patch has been released at the time of publication. System administrators should implement the workarounds below and monitor the GitHub PoC Repository for updates or vendor response.

Workarounds

• Implement a Web Application Firewall (WAF) with XSS protection rules to filter malicious input before it reaches the application
• Apply server-side input validation using allowlist patterns for the mobile parameter (e.g., only digits, dashes, and parentheses)
• Add Content Security Policy (CSP) headers to prevent inline script execution and mitigate the impact of successful XSS attacks
• Use PHP's htmlspecialchars() or equivalent output encoding functions when displaying user input

# Example Apache mod_security rule to block XSS in mobile parameter
SecRule ARGS:mobile "@detectXSS" "id:1001,phase:2,deny,status:403,msg:'XSS Attack Detected in mobile parameter'"