CVE-2024-55198
📋 TL;DR
This vulnerability in Celk Sistemas Celk Saude v.3.1.252.1 allows remote attackers to enumerate valid usernames by analyzing differences in error messages during password recovery attempts. Attackers can determine which accounts exist in the system, facilitating targeted attacks. Organizations using this specific healthcare software version are affected.
💻 Affected Systems
- Celk Sistemas Celk Saude
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers build a complete user directory, enabling targeted phishing, credential stuffing, or brute-force attacks against known valid accounts, potentially leading to unauthorized access to sensitive healthcare data.
Likely Case
Attackers enumerate some valid usernames and use them for targeted social engineering or credential stuffing attacks against those specific accounts.
If Mitigated
With proper monitoring and authentication controls, impact is limited to information disclosure about account existence without enabling actual account compromise.
🎯 Exploit Status
Exploitation requires no authentication and can be automated with simple scripts. Public research demonstrates the vulnerability clearly.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
Contact Celk Sistemas for patch information. Monitor their official channels for security updates.
🔧 Temporary Workarounds
Standardize Error Messages
allModify the password recovery functionality to return identical error messages regardless of whether the username exists or not.
Implement Rate Limiting
allAdd rate limiting to the password recovery endpoint to prevent automated enumeration attempts.
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with rules to detect and block user enumeration patterns
- Monitor authentication logs for unusual patterns of password recovery attempts and implement alerting
🔍 How to Verify
Check if Vulnerable:
Test the password recovery functionality with valid and invalid usernames. If error messages differ (e.g., 'user not found' vs 'recovery email sent'), the system is vulnerable.Check Version:
Check software version in application interface or configuration filesVerify Fix Applied:
After applying fixes, test that both valid and invalid usernames return identical generic error messages during password recovery attempts.📡 Detection & Monitoring
Log Indicators:
- Multiple failed password recovery attempts from single IP
- Patterns of sequential username attempts in authentication logs
Network Indicators:
- Unusual volume of requests to password recovery endpoint
- Requests with systematically varying username parameters
SIEM Query:
source="auth_logs" AND (event="password_recovery" OR event="forgot_password") | stats count by src_ip, username | where count > threshold