CVE-2024-5123: Event Registration System XSS Vulnerability

CVE-2024-5123 Overview

CVE-2024-5123 is a reflected cross-site scripting (XSS) vulnerability in SourceCodester Event Registration System 1.0. The flaw resides in the /registrar/ endpoint, where the searchbar parameter is rendered back to users without proper output encoding. Attackers can craft a malicious URL that executes arbitrary JavaScript in the victim's browser session. The vulnerability is remotely exploitable over the network and requires no authentication. Public disclosure has been made, and the vulnerability is tracked as VDB-265203.

Critical Impact
Remote attackers can inject arbitrary scripts through the searchbar parameter, enabling session hijacking, credential theft, and phishing against authenticated registrars.

Affected Products

Oretnom23 (SourceCodester) Event Registration System 1.0
Deployments exposing the /registrar/ module
Web applications derived from the same codebase

Discovery Timeline

2024-05-20 - CVE CVE-2024-5123 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-5123

Vulnerability Analysis

The vulnerability is a reflected cross-site scripting weakness classified under [CWE-79]. The searchbar query parameter passed to /registrar/ is echoed into the HTML response without sanitization or encoding. When a victim visits an attacker-crafted URL, the browser parses the injected payload as executable script within the application's origin. The attacker inherits the victim's session context and can perform actions on their behalf, exfiltrate document.cookie values, or rewrite page content for phishing.

Root Cause

The root cause is missing input validation and output encoding on the searchbar request parameter. The application concatenates untrusted input directly into HTML output rendered by the registrar search interface. No Content Security Policy (CSP) header is applied to restrict inline script execution, allowing arbitrary payloads to run.

Attack Vector

Exploitation occurs remotely over HTTP without authentication or user interaction beyond clicking a crafted link. An attacker delivers the URL through phishing email, chat, or a malicious website. When the target opens the link while authenticated to the Event Registration System, the injected script executes in their browser session. Technical details are published in the GitHub XSS Vulnerability Report and VulDB #265203.

No verified proof-of-concept code is reproduced here. Refer to the linked advisories for payload specifics.

Detection Methods for CVE-2024-5123

Indicators of Compromise

HTTP GET requests to /registrar/ containing <script>, onerror=, javascript:, or URL-encoded equivalents in the searchbar parameter
Unusual outbound requests from browsers to attacker-controlled domains immediately after visiting the registrar page
Web server access logs showing repeated searchbar parameter fuzzing from a single source IP

Detection Strategies

Deploy web application firewall (WAF) rules that flag script tags, event handlers, and HTML entities in query strings targeting /registrar/
Enable HTTP request logging with full query string capture to support retroactive investigation
Monitor browser Content Security Policy violation reports if CSP is enforced in report-only mode

Monitoring Recommendations

Correlate abnormal searchbar parameter lengths and encoded payloads with authenticated session activity
Alert on outbound HTTP requests from user workstations to newly registered or low-reputation domains
Review session token issuance and reuse patterns for signs of hijacking following suspicious link clicks

How to Mitigate CVE-2024-5123

Immediate Actions Required

Restrict public exposure of the /registrar/ interface using network ACLs or VPN-only access until a fix is applied
Deploy WAF rules that block XSS payload patterns in the searchbar query parameter
Enforce a strict Content Security Policy that disallows inline scripts and untrusted script sources

Patch Information

No vendor patch has been published by Oretnom23 (SourceCodester) for Event Registration System 1.0 at the time of this writing. Operators should apply source-level fixes by adding server-side input validation and context-appropriate output encoding for the searchbar parameter. Track updates through VulDB #265203 CTI.

Workarounds

Apply HTML entity encoding to all user-controlled data rendered in HTML contexts, using functions such as htmlspecialchars() with ENT_QUOTES in PHP
Set HttpOnly and SameSite=Strict flags on session cookies to reduce session theft impact
Add a restrictive Content-Security-Policy response header to block inline script execution

bash

# Example nginx configuration adding a restrictive CSP header
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'" always;
add_header X-XSS-Protection "1; mode=block" always;
add_header X-Content-Type-Options "nosniff" always;