CVE-2024-57423
📋 TL;DR
A Cross-Site Scripting (XSS) vulnerability in CloudClassroom-PHP Project v1.0 allows remote attackers to inject malicious scripts via the exid parameter in the assessment function. This affects all users of CloudClassroom-PHP v1.0 who have the vulnerable component enabled. Attackers can execute arbitrary JavaScript in victims' browsers.
💻 Affected Systems
- CloudClassroom-PHP Project
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal session cookies, perform account takeover, redirect users to malicious sites, or perform actions on behalf of authenticated users.
Likely Case
Attackers steal session tokens to hijack user accounts, deface pages, or redirect users to phishing sites.
If Mitigated
Proper input validation and output encoding prevent script execution, limiting impact to minor UI disruption.
🎯 Exploit Status
XSS vulnerabilities are commonly exploited with simple payloads; public proof-of-concept exists in GitHub references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch exists. Apply workarounds or manually fix the code by implementing input validation and output encoding for the exid parameter.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement server-side validation to allow only expected characters in the exid parameter and sanitize input.
Modify PHP code to validate exid parameter: e.g., if (!preg_match('/^[a-zA-Z0-9]+$/', $_GET['exid'])) { die('Invalid input'); }
Output Encoding
allEncode user-controlled data before outputting in HTML to prevent script execution.
Use htmlspecialchars() in PHP: echo htmlspecialchars($exid, ENT_QUOTES, 'UTF-8');
🧯 If You Can't Patch
- Disable or restrict access to the assessment function if not essential.
- Implement a Web Application Firewall (WAF) with XSS protection rules.
🔍 How to Verify
Check if Vulnerable:
Test by injecting a payload like <script>alert('XSS')</script> into the exid parameter of the assessment function and check if it executes.Check Version:
Check the project version in configuration files or by reviewing the source code for version indicators.Verify Fix Applied:
After applying fixes, test with the same payload; it should not execute and should be displayed as plain text or blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual or long strings in exid parameter logs, especially containing script tags or JavaScript code.
Network Indicators:
- HTTP requests with suspicious payloads in the exid parameter, such as <script> tags.
SIEM Query:
source="web_logs" AND uri="*assessment*" AND query="*exid=*<script>*"