CVE-2021-47856
📋 TL;DR
Easy Cart Shopping Cart 2021 contains a non-persistent cross-site scripting vulnerability in the search module's keyword parameter. Remote attackers can inject malicious JavaScript through search inputs to steal user session cookies, redirect users to malicious sites, or deface the application. This affects all users of Easy Cart Shopping Cart 2021 with the vulnerable search functionality.
💻 Affected Systems
- Easy Cart Shopping Cart
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal administrator session cookies, gain full administrative access to the shopping cart system, modify product prices, steal customer payment information, or install backdoors.
Likely Case
Attackers steal user session cookies to impersonate customers, modify shopping cart contents, redirect users to phishing sites, or deface the search results page with malicious content.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized before execution, preventing session theft and content manipulation.
🎯 Exploit Status
Exploitation requires only a web browser and knowledge of basic XSS payloads. No authentication is needed as the search function is typically public.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor for latest version
Vendor Advisory: https://www.netartmedia.net/easy-cart
Restart Required: No
Instructions:
1. Contact NetArt Media for the latest patched version. 2. Backup your current installation. 3. Apply the vendor-provided patch or update to the latest version. 4. Test search functionality to ensure XSS is mitigated.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize search keywords by removing or encoding HTML/JavaScript characters.
Modify search.php to add: $keyword = htmlspecialchars($_GET['keyword'], ENT_QUOTES, 'UTF-8');
WAF Rule
allDeploy a web application firewall rule to block XSS patterns in search parameters.
Add WAF rule: Detect and block requests with <script>, javascript:, or on* attributes in search parameters.
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) headers to restrict script execution sources.
- Disable the search functionality temporarily if not critical for business operations.
🔍 How to Verify
Check if Vulnerable:
Test by entering <script>alert('XSS')</script> in the search box and check if JavaScript executes.Check Version:
Check the application's admin panel or version file for 'Easy Cart Shopping Cart 2021'.Verify Fix Applied:
After patching, test with the same XSS payload and verify no script execution occurs; check that output is properly encoded.📡 Detection & Monitoring
Log Indicators:
- Unusually long search queries containing <script>, javascript:, or encoded payloads in web server logs.
- Multiple failed search attempts with suspicious patterns.
Network Indicators:
- HTTP requests with search parameters containing JavaScript code or encoded payloads.
SIEM Query:
source="web_logs" AND (uri="*search*" AND (query="*<script>*" OR query="*javascript:*" OR query="*onclick*"))