CVE-2024-23877
📋 TL;DR
CVE-2024-23877 is a stored cross-site scripting (XSS) vulnerability in Cups Easy Purchase & Inventory version 1.0 that allows remote attackers to inject malicious scripts via the currencyid parameter in /cupseasylive/currencycreate.php. This affects all users running the vulnerable version of Cups Easy, particularly those with internet-facing installations. Successful exploitation could lead to session hijacking and unauthorized access to administrative functions.
💻 Affected Systems
- Cups Easy (Purchase & Inventory)
📦 What is this software?
Cups Easy by Ajaysharma
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal administrator session cookies, gain full administrative access to the application, manipulate inventory data, create fraudulent transactions, and potentially pivot to other systems.
Likely Case
Attackers steal authenticated user session cookies to perform unauthorized actions within the application, potentially modifying purchase orders or inventory data.
If Mitigated
With proper input validation and output encoding, the vulnerability would be prevented, and even if exploited, proper session security controls would limit the impact.
🎯 Exploit Status
Exploitation requires the attacker to trick an authenticated user into visiting a malicious URL. The vulnerability is in a parameter that accepts user input without proper sanitization.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-cups-easy
Restart Required: No
Instructions:
1. Check vendor website for updated version. 2. If patch available, backup current installation. 3. Apply patch or upgrade to fixed version. 4. Test functionality after update.
🔧 Temporary Workarounds
Input Validation Filter
allAdd server-side validation to only accept numeric values for currencyid parameter
Modify /cupseasylive/currencycreate.php to validate currencyid parameter using is_numeric() or similar function
Output Encoding
allImplement proper HTML entity encoding for all user-controlled output
Use htmlspecialchars() or similar function when outputting currencyid values in HTML context
🧯 If You Can't Patch
- Implement Web Application Firewall (WAF) rules to block XSS payloads in currencyid parameter
- Restrict access to /cupseasylive/currencycreate.php to trusted IP addresses only
🔍 How to Verify
Check if Vulnerable:
Test by submitting a payload like <script>alert('XSS')</script> in the currencyid parameter and check if script executesCheck Version:
Check application version in admin panel or read application documentation/configuration filesVerify Fix Applied:
Test with same XSS payload after fix - script should not execute and input should be properly sanitized📡 Detection & Monitoring
Log Indicators:
- HTTP requests to /cupseasylive/currencycreate.php with script tags or JavaScript in parameters
- Unusual session activity from same IP with different user agents
Network Indicators:
- HTTP requests containing <script> tags in currencyid parameter
- Outbound connections to suspicious domains after visiting crafted URLs
SIEM Query:
source="web_server" AND uri="/cupseasylive/currencycreate.php" AND (param="currencyid" AND value CONTAINS "<script>" OR value CONTAINS "javascript:")