CVE-2026-3735: Flight Ticket Booking System SQLi Flaw

CVE-2026-3735 Overview

A SQL injection vulnerability has been identified in code-projects Simple Flight Ticket Booking System version 1.0. The vulnerability exists in the SearchResultOneway.php file, where the from parameter is not properly sanitized before being used in SQL queries. This allows remote attackers to manipulate database queries by injecting malicious SQL code through user-supplied input.

Critical Impact
Remote attackers can exploit this SQL injection vulnerability to read, modify, or delete data from the database, potentially compromising sensitive flight booking information, customer records, and system integrity.

Affected Products

Carmelo Simple Flight Ticket Booking System 1.0
code-projects Simple Flight Ticket Booking System

Discovery Timeline

2026-03-08 - CVE-2026-3735 published to NVD
2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-3735

Vulnerability Analysis

This vulnerability represents a classic SQL injection flaw where user input flows directly into database queries without proper sanitization or parameterization. The vulnerable endpoint SearchResultOneway.php accepts search parameters for one-way flight queries, and the from parameter (likely representing the departure airport or city) is directly concatenated into SQL statements. This architectural weakness allows attackers to break out of the intended query structure and execute arbitrary SQL commands against the underlying database.

The application fails to implement fundamental input validation controls, making it susceptible to both in-band and blind SQL injection techniques. Since the vulnerability is network-accessible with no authentication required, any remote attacker can exploit this flaw by simply crafting malicious HTTP requests to the vulnerable endpoint.

Root Cause

The root cause of CVE-2026-3735 is improper input validation (CWE-89: SQL Injection, CWE-74: Injection). The SearchResultOneway.php file constructs database queries by directly embedding user-controlled input from the from parameter without using prepared statements or parameterized queries. This fundamental secure coding violation allows attackers to inject arbitrary SQL syntax that gets executed by the database engine.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or user interaction. An attacker can exploit this flaw by:

Sending a crafted HTTP request to SearchResultOneway.php
Including malicious SQL syntax in the from parameter
The injected SQL is executed by the database server with the application's privileges

The exploitation process involves sending requests containing SQL injection payloads in the from parameter. Attackers may use techniques such as UNION-based injection to extract data, boolean-based blind injection to enumerate database contents, or stacked queries to execute additional statements. For detailed technical information, refer to the GitHub CVE Issue Discussion.

Detection Methods for CVE-2026-3735

Indicators of Compromise

Unusual database queries in application logs containing SQL keywords like UNION, SELECT, OR 1=1, or comment sequences (--, /**/)
HTTP requests to SearchResultOneway.php with abnormally long or malformed from parameter values
Database error messages appearing in application responses or logs
Unexpected data access patterns or bulk data extraction from flight booking tables

Detection Strategies

Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in HTTP parameters
Monitor application logs for requests containing SQL metacharacters in the from parameter
Deploy database activity monitoring to detect anomalous query patterns or unauthorized data access
Use intrusion detection systems (IDS) with SQL injection signature rules

Monitoring Recommendations

Enable detailed logging on the web server for all requests to SearchResultOneway.php
Configure database audit logging to capture query execution patterns and failed authentication attempts
Set up alerts for application errors that may indicate SQL injection attempts
Monitor for unusual outbound data transfers that could indicate data exfiltration

How to Mitigate CVE-2026-3735

Immediate Actions Required

Take the Simple Flight Ticket Booking System offline if it is publicly accessible and contains sensitive data
Implement a Web Application Firewall with SQL injection protection rules as a temporary measure
Audit database access logs for signs of exploitation
Consider replacing the vulnerable application with a more secure alternative

Patch Information

At the time of publication, no official patch has been released by the vendor for this vulnerability. The application is a code-projects demonstration project, and users should check the Code Projects website for any updates. Given the nature of this project, a patch may not be forthcoming.

For additional technical details and vulnerability discussion, refer to the VulDB entry #349713.

Workarounds

Modify SearchResultOneway.php to use prepared statements with parameterized queries for all database interactions
Implement server-side input validation to reject requests containing SQL metacharacters
Deploy a reverse proxy or WAF to filter malicious SQL injection payloads before they reach the application
Restrict network access to the application using firewall rules to limit exposure

bash

# Example Apache ModSecurity rule to block basic SQL injection attempts
SecRule ARGS:from "@rx (?i)(\bunion\b.*\bselect\b|\bor\b\s+\d+\s*=\s*\d+|'.*--|;.*\bdrop\b)" \
    "id:1001,phase:2,deny,status:403,msg:'SQL Injection Attempt Detected'"