CVE-2021-41676
📋 TL;DR
CVE-2021-41676 is an SQL injection vulnerability in the Pharmacy Point of Sale System 1.0 that allows attackers to execute arbitrary SQL commands through the login function. This can lead to authentication bypass, data theft, or complete system compromise. Organizations using this specific software version are affected.
💻 Affected Systems
- oretnom23 Pharmacy Point of Sale System
📦 What is this software?
Pharmacy Point Of Sale System by Pharmacy Point Of Sale System Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover: attacker gains administrative access, steals all pharmacy data (patient records, prescriptions, financial data), and potentially deploys ransomware or other malware.
Likely Case
Authentication bypass leading to unauthorized access to the POS system, allowing manipulation of sales data, theft of customer information, and financial fraud.
If Mitigated
Limited impact with proper network segmentation and input validation, potentially only allowing partial data exposure without full system compromise.
🎯 Exploit Status
Multiple public proof-of-concept scripts are available on GitHub. Exploitation requires minimal technical skill due to the nature of SQL injection in login forms.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
No official patch available. Consider migrating to a supported, secure alternative POS system or implementing workarounds.
🔧 Temporary Workarounds
Web Application Firewall (WAF)
allDeploy a WAF with SQL injection protection rules to block malicious payloads before they reach the application.
Input Validation Filter
allImplement server-side input validation to sanitize all user inputs, particularly in the login parameters.
🧯 If You Can't Patch
- Isolate the system on a segmented network with strict access controls and no internet exposure.
- Implement database-level protections: use parameterized queries, stored procedures, and least privilege database accounts.
🔍 How to Verify
Check if Vulnerable:
Test the login form with SQL injection payloads (e.g., ' OR '1'='1) and observe if authentication bypass occurs or error messages reveal SQL details.Check Version:
Check the application interface or configuration files for version information (typically displays 'Version 1.0' in the interface).Verify Fix Applied:
After implementing workarounds, retest with SQL injection payloads to ensure they are blocked and proper error handling is in place.📡 Detection & Monitoring
Log Indicators:
- Unusual login attempts with SQL keywords in username/password fields
- Multiple failed login attempts from single IP
- Database error messages in application logs
Network Indicators:
- HTTP requests containing SQL injection patterns to actions.php
- Unusual database query patterns from the application server
SIEM Query:
source="web_logs" AND (uri="*actions.php*" AND (request="*OR*" OR request="*UNION*" OR request="*SELECT*"))