CVE-2020-26799
📋 TL;DR
A reflected cross-site scripting (XSS) vulnerability in Luxcal 4.5.2 allows unauthenticated attackers to inject malicious scripts via the index.php page. When exploited, this can enable attackers to steal sensitive data from users who visit a crafted malicious link. All users of Luxcal 4.5.2 are affected.
💻 Affected Systems
- Luxcal Calendar Software
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal session cookies, credentials, and sensitive user data, potentially leading to account takeover and further system compromise.
Likely Case
Attackers create phishing links that steal user session data when clicked, compromising individual user accounts.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized before execution.
🎯 Exploit Status
Exploitation requires tricking users into clicking a malicious link containing the XSS payload.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.5.3 or later
Vendor Advisory: https://www.luxsoft.eu/index.php?pge=dload
Restart Required: No
Instructions:
1. Download the latest version from the Luxcal website. 2. Backup your current installation. 3. Replace the vulnerable files with the patched version. 4. Verify the fix by testing XSS payloads.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize user inputs before processing.
Content Security Policy
allImplement CSP headers to restrict script execution sources.
Header set Content-Security-Policy "default-src 'self'; script-src 'self'"
Header set X-Content-Type-Options "nosniff"
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with XSS protection rules.
- Disable or restrict access to the vulnerable index.php page if not essential.
🔍 How to Verify
Check if Vulnerable:
Test by injecting a simple XSS payload like <script>alert('XSS')</script> into parameters of index.php and checking if it executes.Check Version:
Check the version number in the Luxcal admin panel or configuration files.Verify Fix Applied:
After patching, test the same XSS payloads to ensure they are properly sanitized and do not execute.📡 Detection & Monitoring
Log Indicators:
- Unusual GET requests with script tags or JavaScript code in URL parameters
- Multiple failed login attempts following suspicious URL accesses
Network Indicators:
- HTTP requests containing <script> tags or JavaScript in query strings
- Traffic to known malicious domains after visiting Luxcal pages
SIEM Query:
source="web_server_logs" AND (url="*<script>*" OR url="*javascript:*") AND url="*index.php*"