CVE-2025-60304
📋 TL;DR
Simple Scheduling System 1.0 contains a stored XSS vulnerability in the Subject Description field that allows attackers to inject malicious scripts. When users view scheduled items containing the malicious description, their browsers execute the attacker's code. This affects all users of Simple Scheduling System 1.0 who have access to view scheduled items.
💻 Affected Systems
- Simple Scheduling System
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, redirect users to malicious sites, perform actions on behalf of authenticated users, or install malware through drive-by downloads.
Likely Case
Attackers will typically steal session cookies to hijack user accounts, potentially gaining administrative access to the scheduling system.
If Mitigated
With proper input validation and output encoding, the malicious scripts would be rendered harmless as text rather than executable code.
🎯 Exploit Status
Exploitation requires the ability to create or modify scheduled items with malicious descriptions. This typically requires some level of access to the application.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.1 or later
Vendor Advisory: http://code-projects.com
Restart Required: No
Instructions:
1. Download the latest version from code-projects.com. 2. Backup your current installation. 3. Replace the vulnerable files with the patched version. 4. Verify the fix by testing XSS payloads in the Subject Description field.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize HTML tags and JavaScript from Subject Description field
Implement input sanitization in the PHP code handling Subject Description submissions
Output Encoding
allApply proper HTML encoding when displaying Subject Description content
Use htmlspecialchars() or similar functions when outputting Subject Description data
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with XSS protection rules
- Restrict access to the scheduling system to trusted users only
🔍 How to Verify
Check if Vulnerable:
Test by entering <script>alert('XSS')</script> in the Subject Description field and checking if it executes when viewedCheck Version:
Check the application's version information in the admin panel or about pageVerify Fix Applied:
After patching, test the same XSS payload and verify it displays as plain text rather than executing📡 Detection & Monitoring
Log Indicators:
- Unusual HTML/script patterns in Subject Description field submissions
- Multiple failed login attempts following schedule views
Network Indicators:
- Outbound connections to suspicious domains from user browsers after viewing schedules
SIEM Query:
search 'Subject Description' AND ('<script>' OR 'javascript:' OR 'onload=' OR 'onerror=')