CVE-2024-48761
📋 TL;DR
This is a reflected cross-site scripting (XSS) vulnerability in Celk Sistemas Celk Saude healthcare software version 3.1.252.1. An attacker can inject malicious JavaScript code via the 'erro' parameter, which gets executed in victims' browsers when they visit a specially crafted URL. Healthcare organizations using this vulnerable version are affected.
💻 Affected Systems
- Celk Sistemas Celk Saude
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker steals healthcare staff credentials, accesses sensitive patient data, modifies medical records, or performs administrative actions in the healthcare system.
Likely Case
Attacker steals session cookies to hijack user accounts, performs phishing attacks, or defaces the application interface.
If Mitigated
Limited to temporary annoyance or minor data exposure if proper input validation and output encoding are implemented.
🎯 Exploit Status
Exploitation requires tricking users into clicking malicious links. No authentication is needed to trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after v.3.1.252.1
Vendor Advisory: Not publicly available
Restart Required: No
Instructions:
1. Contact Celk Sistemas for the patched version. 2. Backup current installation. 3. Apply the vendor-provided patch or upgrade to latest version. 4. Test functionality after patching.
🔧 Temporary Workarounds
Web Application Firewall (WAF) Rules
allConfigure WAF to block requests containing malicious JavaScript patterns in the 'erro' parameter
Input Validation Filter
allImplement server-side validation to sanitize the 'erro' parameter before processing
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) headers to restrict script execution
- Disable or restrict access to the vulnerable endpoint if not critical
🔍 How to Verify
Check if Vulnerable:
Test by accessing the application with a payload like: /page?erro=<script>alert('XSS')</script> and check if script executesCheck Version:
Check application version in admin panel or configuration filesVerify Fix Applied:
Retest with the same payload after patching - script should not execute and input should be properly encoded📡 Detection & Monitoring
Log Indicators:
- HTTP requests containing script tags or JavaScript code in 'erro' parameter
- Unusual error parameter values in access logs
Network Indicators:
- HTTP requests with encoded script payloads in query parameters
- Multiple failed login attempts following XSS payload delivery
SIEM Query:
source="web_logs" AND (uri="*erro=*script*" OR uri="*erro=*javascript:*" OR uri="*erro=*onerror=*")