CVE-2023-48207
📋 TL;DR
CVE-2023-48207 is a CSV injection vulnerability in Availability Booking Calendar 5.0 that allows attackers to inject malicious formulas into exported CSV files via the unique ID field. This affects organizations using the vulnerable version of the booking calendar software for reservation management. When users open the exported CSV files in spreadsheet applications like Excel, the formulas can execute arbitrary commands.
💻 Affected Systems
- Availability Booking Calendar
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could execute arbitrary commands on victim systems when users open malicious CSV files, potentially leading to full system compromise, data theft, or ransomware deployment.
Likely Case
Attackers trick users into opening manipulated CSV exports containing malicious formulas, leading to local command execution, data exfiltration, or credential theft from the victim's machine.
If Mitigated
With proper user awareness training and security controls, the impact is limited to potential data manipulation in spreadsheets without command execution.
🎯 Exploit Status
Exploitation requires access to the booking system interface to manipulate reservation data. The CSV injection technique is well-documented and easy to implement.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.0.1 or later
Vendor Advisory: https://wordpress.org/plugins/booking-calendar/
Restart Required: No
Instructions:
1. Log into your WordPress admin panel. 2. Navigate to Plugins > Installed Plugins. 3. Find Availability Booking Calendar. 4. Click 'Update Now' if update is available. 5. Alternatively, download latest version from WordPress repository and replace plugin files.
🔧 Temporary Workarounds
Disable CSV Export
allTemporarily disable CSV export functionality in the Reservations list component
Input Sanitization
allAdd custom input validation to sanitize unique ID field before CSV export
🧯 If You Can't Patch
- Implement strict user access controls to limit who can modify reservation data
- Train users to never open CSV files from untrusted sources and to disable automatic formula execution in spreadsheet applications
🔍 How to Verify
Check if Vulnerable:
Check if Availability Booking Calendar version is 5.0 by navigating to WordPress Plugins page or checking wp-content/plugins/booking-calendar/readme.txtCheck Version:
grep 'Version' /path/to/wordpress/wp-content/plugins/booking-calendar/readme.txtVerify Fix Applied:
Verify plugin version is 5.0.1 or higher in WordPress admin panel under Plugins > Installed Plugins📡 Detection & Monitoring
Log Indicators:
- Unusual CSV export requests
- Multiple reservation modifications from single user
- Suspicious characters in unique ID fields
Network Indicators:
- Large CSV file downloads from booking system
- Unusual outbound connections after CSV file access
SIEM Query:
source="wordpress" AND (event="csv_export" OR event="reservation_modified") AND (data contains "=", "+", "-", "@" OR data matches /^[A-Za-z][0-9]*\(/)