CVE-2025-70094
📋 TL;DR
This cross-site scripting (XSS) vulnerability in OpenSourcePOS allows attackers to inject malicious scripts into the Item Category parameter during barcode generation. When exploited, it enables execution of arbitrary JavaScript in victims' browsers, potentially compromising user sessions or stealing sensitive data. All users of OpenSourcePOS v3.4.1 with the Generate Item Barcode function enabled are affected.
💻 Affected Systems
- OpenSourcePOS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, gain full control of the POS system, manipulate transactions, or exfiltrate sensitive customer payment data.
Likely Case
Attackers could perform session hijacking, redirect users to malicious sites, or deface the application interface with injected content.
If Mitigated
With proper input validation and output encoding, the vulnerability would be neutralized, preventing script execution while maintaining barcode functionality.
🎯 Exploit Status
Exploitation requires access to the barcode generation interface, which typically requires some level of authentication. The vulnerability is in the web interface component.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after pull request #4357 is merged
Vendor Advisory: https://github.com/opensourcepos/opensourcepos/pull/4357
Restart Required: No
Instructions:
1. Update OpenSourcePOS to the latest version that includes the fix from pull request #4357. 2. Apply the patch that adds proper input validation and output encoding for the Item Category parameter. 3. Verify the fix by testing barcode generation with various inputs.
🔧 Temporary Workarounds
Disable Barcode Generation
allTemporarily disable the Generate Item Barcode function to prevent exploitation while waiting for patch
Modify application configuration to remove or disable barcode generation functionality
Input Validation Filter
allImplement server-side input validation to reject malicious payloads in Item Category parameter
Add input sanitization in the barcode generation controller to strip or escape HTML/JavaScript characters
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with XSS protection rules to block malicious payloads
- Restrict access to the barcode generation function to trusted users only using role-based access controls
🔍 How to Verify
Check if Vulnerable:
Test the Generate Item Barcode function by entering a test payload like <script>alert('XSS')</script> in the Item Category field and check if script executesCheck Version:
Check the OpenSourcePOS version in the application's about page or configuration filesVerify Fix Applied:
After patching, repeat the test with the same payload and verify no script execution occurs and input is properly sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual characters or script tags in Item Category parameter logs
- Multiple failed barcode generation attempts with special characters
Network Indicators:
- HTTP requests containing script tags or JavaScript in Item Category parameter
- Unusual outbound connections from the POS system after barcode generation
SIEM Query:
source="opensourcepos_logs" AND (ItemCategory CONTAINS "<script>" OR ItemCategory CONTAINS "javascript:" OR ItemCategory CONTAINS "onerror=" OR ItemCategory CONTAINS "onload=")