CVE-2025-40731: Daily Expense Manager SQL Injection Flaw

CVE-2025-40731 Overview

CVE-2025-40731 is a SQL injection vulnerability affecting Daily Expense Manager v1.0, a web-based expense tracking application developed by code-projects. This vulnerability allows an authenticated attacker to manipulate database operations by injecting malicious SQL statements through unsanitized input parameters in the /update.php endpoint. The affected parameters include pname, pprice, and id, which are directly incorporated into database queries without proper validation or sanitization.

Critical Impact

An attacker can exploit this SQL injection vulnerability to retrieve, create, update, and delete arbitrary database records, potentially compromising all stored financial data and user credentials within the Daily Expense Manager application.

Affected Products

• Code-projects Daily Expense Manager v1.0
• Systems running Daily Expense Manager with the vulnerable /update.php endpoint
• Deployments where the pname, pprice, and id parameters are exposed without input validation

Discovery Timeline

• June 30, 2025 - CVE-2025-40731 published to NVD
• July 7, 2025 - Last updated in NVD database

Technical Details for CVE-2025-40731

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) exists in the /update.php file of Daily Expense Manager v1.0. The application fails to implement proper input validation and parameterized queries when processing user-supplied data through the pname (product name), pprice (product price), and id parameters. When a user submits a request to update expense records, these parameters are directly concatenated into SQL query strings, creating an injection point that attackers can exploit.

The vulnerability requires low-privilege authentication to exploit, meaning an attacker must have a valid user account. However, once authenticated, the attacker gains significant control over the underlying database, with the ability to perform full CRUD (Create, Read, Update, Delete) operations on database content beyond their authorized scope.

Root Cause

The root cause of CVE-2025-40731 is the direct use of user-controlled input in SQL query construction without employing prepared statements or parameterized queries. The /update.php script concatenates the pname, pprice, and id parameter values directly into SQL statements, enabling attackers to break out of the intended query context and inject arbitrary SQL commands.

Attack Vector

The attack vector for this vulnerability is network-based, targeting the /update.php endpoint. An authenticated attacker can craft malicious HTTP requests containing SQL injection payloads in any of the three vulnerable parameters. The attacker could leverage techniques such as:

• UNION-based injection: Extracting data from other database tables by appending UNION SELECT statements
• Time-based blind injection: Inferring database contents through response timing differences
• Error-based injection: Extracting data through verbose database error messages
• Stacked queries: Executing additional SQL statements to modify or delete data

The vulnerability allows network-accessible exploitation with low attack complexity, requiring only valid user credentials to initiate the attack. Successful exploitation grants the attacker the ability to manipulate the entire database backend, potentially compromising user credentials, financial records, and application integrity.

Detection Methods for CVE-2025-40731

Indicators of Compromise

• Unusual or malformed requests to /update.php containing SQL syntax characters such as single quotes ('), double dashes (--), semicolons (;), or UNION SELECT keywords
• Database error messages appearing in application logs indicating SQL syntax errors
• Unexpected database modifications or data exfiltration patterns in audit logs
• Anomalous query execution times suggesting time-based blind SQL injection attempts

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns targeting the pname, pprice, and id parameters
• Implement database activity monitoring to identify unusual query patterns or unauthorized data access
• Enable application-level logging for all requests to /update.php and analyze for injection attempts
• Configure SentinelOne Singularity platform to monitor for web application attack patterns and database anomalies

Monitoring Recommendations

• Monitor web server access logs for repeated requests to /update.php with suspicious parameter values
• Set up alerts for database queries containing SQL injection indicators such as UNION, SELECT, DROP, or comment sequences
• Track failed login attempts followed by requests to vulnerable endpoints as potential reconnaissance activity
• Review audit logs for bulk data exports or unusual data modification patterns

How to Mitigate CVE-2025-40731

Immediate Actions Required

• Restrict access to the Daily Expense Manager application to trusted networks only until a patch is available
• Implement Web Application Firewall (WAF) rules to filter malicious input targeting /update.php
• Review and sanitize all user inputs in the pname, pprice, and id parameters at the application level
• Consider temporarily disabling the /update.php functionality if business operations permit

Patch Information

At the time of publication, no vendor patch has been released for this vulnerability. Organizations using Daily Expense Manager v1.0 should monitor the INCIBE Security Notice for updates and remediation guidance. Given the nature of this open-source project, organizations may need to implement code-level fixes independently or consider migrating to an alternative expense management solution with better security practices.

Workarounds

• Implement prepared statements and parameterized queries in the /update.php file to prevent SQL injection
• Deploy input validation to ensure id contains only numeric values and pname/pprice are properly escaped
• Use stored procedures with input validation to abstract database operations from direct user input
• Implement least privilege database permissions to limit the damage potential if exploitation occurs
• Add rate limiting to the /update.php endpoint to slow down automated injection attempts

# Example .htaccess rule to restrict access to update.php
<Files "update.php">
    Order Deny,Allow
    Deny from all
    Allow from 192.168.1.0/24
    # Restrict to internal network only until patched
</Files>