CVE-2023-51296
📋 TL;DR
PHPJabbers Event Booking Calendar v4.0 contains a cross-site scripting vulnerability in multiple parameters that allows attackers to inject malicious scripts. When exploited, this can lead to session hijacking, credential theft, or redirection to malicious sites. Any organization using this specific version of the calendar software is affected.
💻 Affected Systems
- PHPJabbers Event Booking Calendar
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator credentials, take over admin accounts, deface websites, or redirect users to malicious sites, potentially leading to complete system compromise.
Likely Case
Attackers inject malicious scripts to steal user session cookies or credentials, enabling account takeover of regular users or administrators who view the affected pages.
If Mitigated
With proper input validation and output encoding, the impact is limited to script execution in user browsers without server compromise.
🎯 Exploit Status
Proof of concept code is publicly available on Packet Storm. The vulnerability requires no authentication and has simple exploitation vectors.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: No
Instructions:
1. Check PHPJabbers website for updated version
2. If update available, backup current installation
3. Replace vulnerable files with patched version
4. Test functionality after update
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize the vulnerable parameters
// PHP example: htmlspecialchars($_POST['parameter'], ENT_QUOTES, 'UTF-8')
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 Web Application Firewall (WAF) rules to block XSS payloads in the vulnerable parameters
- Disable or restrict access to the Event Booking Calendar component if not essential
🔍 How to Verify
Check if Vulnerable:
Check if Event Booking Calendar version is 4.0 by examining the software version in admin panel or source codeCheck Version:
Check admin panel or examine PHP files for version informationVerify Fix Applied:
Test the vulnerable parameters with XSS payloads to ensure they are properly sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual POST/GET requests containing script tags in name, title, or SMS parameters
- Multiple failed XSS attempts in web server logs
Network Indicators:
- HTTP requests with script tags or JavaScript in parameter values
- Unusual traffic patterns to calendar endpoints
SIEM Query:
source="web_logs" AND (parameter="name" OR parameter="title" OR parameter="plugin_sms_*") AND (value="<script>" OR value="javascript:")