CVE-2025-40618: Bookgy SQL Injection Vulnerability

CVE-2025-40618 Overview

CVE-2025-40618 is a critical SQL injection vulnerability affecting the Bookgy booking management application. This vulnerability exists in the /bkg_imprimir_comprobante.php endpoint, where the IDRESERVA parameter fails to properly sanitize user input before incorporating it into SQL queries. Successful exploitation allows an unauthenticated remote attacker to retrieve, create, update, and delete database contents by sending specially crafted HTTP requests.

Critical Impact

An unauthenticated attacker can fully compromise the database backend, enabling data exfiltration, data manipulation, and potential destruction of business-critical booking information.

Affected Products

• Bookgy booking management application
• Deployments exposing /bkg_imprimir_comprobante.php endpoint

Discovery Timeline

• 2025-04-29 - CVE-2025-40618 published to NVD
• 2025-10-14 - Last updated in NVD database

Technical Details for CVE-2025-40618

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) occurs when the Bookgy application processes HTTP requests containing the IDRESERVA parameter within the /bkg_imprimir_comprobante.php script. The parameter value is directly concatenated or improperly escaped before being included in SQL queries, allowing attackers to inject arbitrary SQL commands. Since the vulnerability requires no authentication and can be exploited remotely over the network, it presents a significant risk to any organization running an exposed Bookgy instance.

The exploitation of this vulnerability grants attackers complete control over database operations, including the ability to extract sensitive booking data, customer information, and potentially credentials stored in the database. Additionally, attackers may modify or delete existing records, causing operational disruption and data integrity issues.

Root Cause

The root cause is improper input validation and missing parameterized query implementation in the IDRESERVA parameter handling within /bkg_imprimir_comprobante.php. The application fails to sanitize or escape special SQL characters, and does not use prepared statements or parameterized queries to safely handle user-supplied input.

Attack Vector

The attack is conducted over the network by sending a malicious HTTP request to the vulnerable /bkg_imprimir_comprobante.php endpoint. An attacker crafts a request with SQL injection payloads in the IDRESERVA parameter. When the application processes this request, the injected SQL commands execute against the backend database with the privileges of the application's database connection.

Typical SQL injection techniques such as UNION-based, error-based, blind, and time-based attacks may be effective depending on the database configuration and error handling. Attackers can enumerate database structure, extract sensitive data, modify records, or drop tables entirely. No authentication or user interaction is required for exploitation.

Detection Methods for CVE-2025-40618

Indicators of Compromise

• Unusual or malformed requests to /bkg_imprimir_comprobante.php containing SQL syntax in the IDRESERVA parameter
• Database logs showing unexpected queries, particularly those with UNION SELECT, OR 1=1, or other SQL injection patterns
• Anomalous data access patterns or bulk data extraction from booking-related tables
• Unexpected database modifications, deletions, or schema changes

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block SQL injection patterns targeting the IDRESERVA parameter
• Monitor HTTP access logs for requests to /bkg_imprimir_comprobante.php with suspicious characters such as single quotes, double dashes, semicolons, or UNION keywords
• Configure database activity monitoring to alert on unusual query patterns or privilege escalation attempts
• Deploy intrusion detection systems (IDS) with signatures for common SQL injection attack payloads

Monitoring Recommendations

• Enable detailed logging for the web application and database to capture full request bodies and query execution
• Set up alerts for failed SQL queries or syntax errors that may indicate injection attempts
• Regularly review database access logs for unauthorized read or write operations
• Monitor for new or modified database user accounts that could indicate successful exploitation

How to Mitigate CVE-2025-40618

Immediate Actions Required

• Restrict public access to /bkg_imprimir_comprobante.php using network segmentation or firewall rules until a patch is applied
• Implement input validation on the IDRESERVA parameter to accept only expected data types (e.g., numeric values)
• Deploy a Web Application Firewall (WAF) with SQL injection protection rules as a temporary defensive measure
• Review database logs for signs of prior exploitation and assess potential data exposure

Patch Information

At the time of publication, no specific vendor patch information has been released. Organizations should monitor the INCIBE Security Notice for updates regarding official patches or remediation guidance from the vendor.

Workarounds

• Implement strict input validation to ensure the IDRESERVA parameter only accepts integer values
• Modify the application code to use parameterized queries or prepared statements for all database interactions
• Restrict database user privileges to the minimum required operations to limit the impact of successful exploitation
• Place the application behind a reverse proxy with SQL injection filtering capabilities
• Consider taking the vulnerable endpoint offline until proper remediation can be implemented

# Example: Block access to vulnerable endpoint via Apache .htaccess
<Files "bkg_imprimir_comprobante.php">
    Order Deny,Allow
    Deny from all
    # Allow only from trusted internal networks
    Allow from 10.0.0.0/8
    Allow from 192.168.0.0/16
</Files>