CVE-2025-25221: Luxsoft Luxcal Calendar SQLi Vulnerability

CVE-2025-25221 Overview

CVE-2025-25221 is a critical SQL injection vulnerability affecting LuxCal Web Calendar, a popular web-based calendar application developed by Luxsoft. The vulnerability exists in the pdf.php file and affects versions prior to 5.3.3M (MySQL version) and prior to 5.3.3L (SQLite version). If successfully exploited, an attacker can delete, alter, or retrieve sensitive information stored in the application's database without authentication.

Critical Impact

This SQL injection vulnerability allows unauthenticated remote attackers to manipulate database contents, potentially leading to complete data compromise, unauthorized data modification, or data destruction.

Affected Products

• LuxCal Web Calendar prior to version 5.3.3M (MySQL version)
• LuxCal Web Calendar prior to version 5.3.3L (SQLite version)
• Luxsoft LuxCal Web Calendar (all database variants before patched versions)

Discovery Timeline

• 2025-02-18 - CVE-2025-25221 published to NVD
• 2025-09-15 - Last updated in NVD database

Technical Details for CVE-2025-25221

Vulnerability Analysis

This vulnerability is classified as CWE-89 (SQL Injection), which occurs when user-supplied input is incorporated into SQL queries without proper sanitization or parameterization. In the case of CVE-2025-25221, the pdf.php file in LuxCal Web Calendar fails to adequately validate or escape user input before including it in database queries.

The attack can be executed remotely over the network without requiring any prior authentication or user interaction. Due to the lack of input validation, attackers can inject arbitrary SQL commands that the database engine will execute with the same privileges as the application's database user. This can result in unauthorized access to sensitive calendar data, user credentials, and administrative information stored within the database.

Root Cause

The root cause of this vulnerability lies in improper input validation within the pdf.php file. The application directly incorporates user-controlled parameters into SQL queries without using prepared statements, parameterized queries, or adequate input sanitization. This classic SQL injection pattern allows malicious SQL code to be injected and executed by the database management system.

Both the MySQL and SQLite versions of LuxCal Web Calendar are affected, indicating that the vulnerable code path exists in a shared component that handles database operations regardless of the underlying database engine.

Attack Vector

The vulnerability is exploitable via network-based attacks targeting the pdf.php endpoint. An attacker can craft malicious HTTP requests containing SQL injection payloads in vulnerable parameters. Since no authentication is required and no user interaction is needed, this represents a highly accessible attack surface.

Successful exploitation allows attackers to:

• Extract sensitive data including user credentials and calendar entries
• Modify or delete database records
• Potentially escalate privileges within the application
• Compromise the confidentiality, integrity, and availability of stored data

For technical details on exploitation patterns, refer to the JVN Security Advisory which provides additional context on this vulnerability.

Detection Methods for CVE-2025-25221

Indicators of Compromise

• Unusual or malformed HTTP requests to pdf.php containing SQL syntax characters such as single quotes, semicolons, or SQL keywords
• Database error messages appearing in application logs or HTTP responses
• Unexpected database queries in database server logs, particularly those containing UNION SELECT, DROP, DELETE, or UPDATE statements
• Evidence of data exfiltration or unauthorized data modifications in calendar entries

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block SQL injection patterns in requests to pdf.php
• Monitor web server access logs for requests containing SQL injection signatures targeting the LuxCal application
• Enable database query logging and alert on suspicious query patterns or syntax errors
• Deploy intrusion detection systems (IDS) with signatures for common SQL injection attack vectors

Monitoring Recommendations

• Configure real-time alerting for anomalous database activity including mass SELECT operations or schema modifications
• Establish baseline metrics for normal pdf.php access patterns and alert on deviations
• Implement database activity monitoring to track queries executed against calendar-related tables
• Review web application logs regularly for evidence of reconnaissance or exploitation attempts

How to Mitigate CVE-2025-25221

Immediate Actions Required

• Upgrade LuxCal Web Calendar to version 5.3.3M or later for MySQL deployments immediately
• Upgrade LuxCal Web Calendar to version 5.3.3L or later for SQLite deployments immediately
• If immediate patching is not possible, restrict access to pdf.php via web server configuration
• Conduct a database integrity review to identify any unauthorized modifications

Patch Information

Luxsoft has released patched versions of LuxCal Web Calendar that address this SQL injection vulnerability. Users should upgrade to version 5.3.3M (MySQL) or 5.3.3L (SQLite) or later. The updated software packages are available from the Luxsoft Download Page. Additional discussion and support regarding the patch can be found in the Luxsoft Forum.

Workarounds

• Restrict network access to the LuxCal Web Calendar application using firewall rules or access control lists
• Temporarily disable or rename the pdf.php file if PDF generation functionality is not critical to operations
• Implement a reverse proxy or WAF with SQL injection filtering rules in front of the application
• Apply principle of least privilege to the database user account used by LuxCal to minimize impact of successful exploitation

# Example: Restrict access to pdf.php via Apache .htaccess
<Files "pdf.php">
    Order Deny,Allow
    Deny from all
    # Allow only trusted IP addresses
    Allow from 192.168.1.0/24
</Files>