CVE-2023-33563
📋 TL;DR
CVE-2023-33563 is an authentication bypass vulnerability in PHP Jabbers Time Slots Booking Calendar 3.3 that allows remote attackers to take over user accounts by changing email addresses and passwords without proper verification. This affects all users of the vulnerable software version. Attackers can compromise any account to gain unauthorized access.
💻 Affected Systems
- PHP Jabbers Time Slots Booking Calendar
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of all user accounts, allowing attackers to access sensitive booking data, modify reservations, and potentially pivot to other systems if credentials are reused.
Likely Case
Targeted account takeover of specific users, leading to unauthorized access to booking information and potential data theft.
If Mitigated
Limited impact with proper authentication controls and monitoring, though the vulnerability still exists.
🎯 Exploit Status
Exploitation requires access to the profile page but doesn't require authentication to change credentials. The vulnerability is documented in public disclosures.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version after 3.3
Vendor Advisory: https://www.phpjabbers.com/time-slots-booking-calendar/
Restart Required: No
Instructions:
1. Upgrade to the latest version of PHP Jabbers Time Slots Booking Calendar. 2. Verify the patch is applied by checking version number. 3. Test profile modification functionality.
🔧 Temporary Workarounds
Disable Profile Modification
allTemporarily disable the profile page functionality to prevent exploitation.
# Modify application code to remove or restrict access to profile modification features
Implement Additional Authentication
allAdd multi-factor authentication or additional verification steps for profile changes.
# Implement session validation and re-authentication for sensitive actions
🧯 If You Can't Patch
- Implement web application firewall rules to block suspicious profile modification requests
- Enable detailed logging of all profile modification attempts and monitor for unauthorized changes
🔍 How to Verify
Check if Vulnerable:
Check if running PHP Jabbers Time Slots Booking Calendar version 3.3. Attempt to change email/password without proper verification.Check Version:
# Check application version in admin panel or configuration filesVerify Fix Applied:
After patching, verify that email/password changes require proper authentication and verification steps.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful profile modifications
- Profile changes from unusual IP addresses or user agents
Network Indicators:
- HTTP POST requests to profile update endpoints without proper authentication headers
SIEM Query:
source="web_logs" AND (uri_path="/profile/update" OR uri_path="/profile/save") AND NOT (user_authenticated="true" OR session_valid="true")