CVE-2026-5660: Construction Management System SQLi Flaw

CVE-2026-5660 Overview

A SQL injection vulnerability has been identified in itsourcecode Construction Management System version 1.0. The vulnerability exists in the /borrowed_equip.php file within the Parameter Handler component, where improper handling of the emp argument allows attackers to inject malicious SQL queries. This flaw can be exploited remotely by authenticated attackers to manipulate database operations, potentially leading to unauthorized data access, modification, or deletion.

Critical Impact

Remote attackers with low privileges can exploit this SQL injection vulnerability to extract sensitive data, modify database records, or potentially compromise the underlying database server through the emp parameter in the borrowed equipment functionality.

Affected Products

• itsourcecode Construction Management System 1.0
• /borrowed_equip.php Parameter Handler component

Discovery Timeline

• 2026-04-06 - CVE-2026-5660 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2026-5660

Vulnerability Analysis

This SQL injection vulnerability stems from inadequate input validation in the Construction Management System's borrowed equipment functionality. The emp parameter in /borrowed_equip.php is directly incorporated into SQL queries without proper sanitization or parameterized query implementation. When user-supplied input is concatenated directly into SQL statements, attackers can craft malicious input strings that alter the intended query logic.

The vulnerability is classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), which encompasses injection flaws where untrusted data is sent to an interpreter as part of a command or query. The exploit has been publicly disclosed and documented in vulnerability databases, increasing the risk of exploitation in the wild.

Root Cause

The root cause of this vulnerability is the lack of input sanitization and the absence of parameterized queries (prepared statements) when processing the emp argument. The application directly concatenates user-supplied input into SQL query strings, allowing special SQL characters and commands to be interpreted as part of the query structure rather than as data values. This classic SQL injection pattern indicates that secure coding practices were not followed during development.

Attack Vector

The attack can be initiated remotely over the network by any authenticated user with access to the borrowed equipment functionality. An attacker can manipulate the emp parameter to inject arbitrary SQL commands. The network-based attack vector with low complexity and no user interaction required makes this vulnerability particularly dangerous for publicly accessible installations.

Typical exploitation scenarios include:

• Extracting sensitive data from database tables using UNION-based injection
• Bypassing authentication checks through boolean-based blind injection
• Modifying or deleting records via stacked queries (if supported)
• Enumerating database structure for further attacks

For technical details on the specific exploitation methodology, refer to the GitHub Issue Discussion and VulDB Vulnerability #355484.

Detection Methods for CVE-2026-5660

Indicators of Compromise

• Unusual SQL error messages in application logs referencing /borrowed_equip.php
• Abnormal query patterns in database logs, particularly involving the emp parameter
• Unexpected database queries containing SQL keywords like UNION, SELECT, DROP, or comment sequences (--, /*)
• Access logs showing requests to /borrowed_equip.php with encoded special characters or unusually long parameter values

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect SQL injection patterns in HTTP requests targeting /borrowed_equip.php
• Configure database activity monitoring to alert on anomalous query patterns, especially those involving string concatenation or multiple statement execution
• Implement application-level logging to capture all parameter values submitted to the vulnerable endpoint
• Use SIEM correlation rules to identify potential exploitation attempts across network and application logs

Monitoring Recommendations

• Enable verbose logging for the Construction Management System application to capture request parameters
• Monitor database query logs for syntax errors that may indicate failed injection attempts
• Set up alerts for high-frequency requests to /borrowed_equip.php from single IP addresses
• Review access logs periodically for requests containing URL-encoded special characters in the emp parameter

How to Mitigate CVE-2026-5660

Immediate Actions Required

• Restrict access to the Construction Management System to trusted networks only until a patch is available
• Implement WAF rules to block requests containing SQL injection patterns targeting the emp parameter
• Consider disabling or removing the /borrowed_equip.php functionality if not critical to operations
• Review database user permissions to ensure the application uses a least-privilege account

Patch Information

As of the last update on 2026-04-07, no official vendor patch has been released for this vulnerability. Monitor the IT Source Code Blog for potential updates and security advisories. Given that the Construction Management System is an open-source project, organizations may need to implement custom fixes or consider alternative solutions.

For additional vulnerability intelligence, refer to the VulDB CTI for #355484.

Workarounds

• Implement input validation using allowlists to restrict the emp parameter to expected numeric or alphanumeric formats
• Apply a virtual patch through WAF or reverse proxy to sanitize the emp parameter before it reaches the application
• Modify the source code to use parameterized queries (prepared statements) for all database interactions involving user input
• Deploy network segmentation to isolate the application server and database from other network segments

# Example WAF rule for ModSecurity to block SQL injection in emp parameter
SecRule ARGS:emp "@detectSQLi" \
    "id:100001,\
    phase:2,\
    block,\
    msg:'SQL Injection attempt detected in emp parameter',\
    logdata:'Matched Data: %{MATCHED_VAR}',\
    severity:'CRITICAL'"