CVE-2023-36132
📋 TL;DR
PHP Jabbers Availability Booking Calendar 5.0 has an incorrect access control vulnerability that allows attackers to bypass authentication and gain unauthorized access to administrative functions. This affects all installations of version 5.0 that are exposed to untrusted users. Attackers can exploit this without valid credentials to compromise the booking system.
💻 Affected Systems
- PHP Jabbers Availability Booking Calendar
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to modify booking data, steal customer information, deface the website, or install backdoors for persistent access.
Likely Case
Unauthorized access to administrative panels leading to data manipulation, booking system disruption, and potential data exfiltration of customer information.
If Mitigated
Limited impact with proper network segmentation and monitoring, though authentication bypass would still allow some unauthorized access.
🎯 Exploit Status
The vulnerability allows authentication bypass without credentials. Public details exist in the referenced Medium article.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 5.1 or later
Vendor Advisory: https://www.phpjabbers.com/availability-booking-calendar/
Restart Required: No
Instructions:
1. Download latest version from PHP Jabbers website. 2. Backup current installation. 3. Replace vulnerable files with patched version. 4. Test functionality.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict access to the booking calendar admin interface to trusted IP addresses only
Web Application Firewall Rules
allImplement WAF rules to block unauthorized access patterns to admin endpoints
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the booking system from other critical infrastructure
- Enable detailed logging and monitoring for unauthorized access attempts to admin interfaces
🔍 How to Verify
Check if Vulnerable:
Check if running version 5.0 by examining the application files or admin panel version displayCheck Version:
Check the application's admin panel or examine the main application files for version informationVerify Fix Applied:
Verify version is 5.1 or later and test authentication requirements for admin functions📡 Detection & Monitoring
Log Indicators:
- Unauthorized access to admin URLs without authentication
- Multiple failed login attempts followed by successful admin access
Network Indicators:
- Direct access to admin endpoints without preceding authentication requests
SIEM Query:
source="web_logs" AND (url="*/admin/*" OR url="*/administrator/*") AND NOT (status="401" OR status="403") AND user_agent NOT IN ("trusted_bots")