CVE-2026-5553: Online Cellphone System SQLi Vulnerability

CVE-2026-5553 Overview

A SQL Injection vulnerability has been identified in itsourcecode Online Cellphone System 1.0. This vulnerability affects the Parameter Handler component, specifically within the /cp/available.php file. Manipulation of the Name argument allows attackers to inject malicious SQL queries, potentially compromising the underlying database. The attack can be launched remotely, and the exploit is publicly available.

Critical Impact

Remote attackers can exploit this SQL injection vulnerability to extract sensitive data, modify database contents, or potentially gain unauthorized access to the underlying system through malicious SQL query manipulation.

Affected Products

• itsourcecode Online Cellphone System 1.0
• /cp/available.php Parameter Handler component

Discovery Timeline

• 2026-04-05 - CVE-2026-5553 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2026-5553

Vulnerability Analysis

This vulnerability is classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), which is the parent category for injection flaws. The Online Cellphone System fails to properly sanitize user-supplied input in the Name parameter before incorporating it into SQL queries. This allows an attacker to inject arbitrary SQL commands that will be executed by the database engine.

The vulnerable endpoint /cp/available.php appears to handle product availability checks or similar functionality, accepting user input through the Name parameter. Without proper input validation or parameterized queries, the application directly concatenates user input into SQL statements, creating a classic SQL injection attack surface.

Root Cause

The root cause of this vulnerability stems from improper input validation and the absence of parameterized queries or prepared statements in the affected PHP file. The application directly incorporates user-controlled data from the Name parameter into SQL query construction without sanitization or escaping, allowing attackers to break out of the intended query context and execute arbitrary SQL commands.

Attack Vector

The attack vector is network-based, requiring low privileges and no user interaction. An attacker can exploit this vulnerability by sending crafted HTTP requests to the /cp/available.php endpoint with malicious SQL payload in the Name parameter. The vulnerability can be exploited to perform various SQL injection attacks including:

• Union-based attacks to extract data from other database tables
• Boolean-based blind injection to infer database contents through true/false responses
• Time-based blind injection using SQL delay functions to extract data
• Error-based injection to retrieve database error messages containing sensitive information

Technical details and proof-of-concept information are available in the GitHub Issue Discussion and VulDB entry #355323.

Detection Methods for CVE-2026-5553

Indicators of Compromise

• Unusual SQL error messages in application logs containing syntax errors or unexpected query patterns
• Abnormal requests to /cp/available.php with special characters in the Name parameter such as single quotes, double dashes, or UNION keywords
• Database query logs showing unauthorized SELECT, INSERT, UPDATE, or DELETE operations
• Unexpected data exfiltration patterns or database access from the web application user account

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in HTTP requests targeting /cp/available.php
• Configure intrusion detection systems to alert on common SQL injection signatures including UNION SELECT, OR 1=1, --, and encoded variants
• Monitor application logs for repeated failed requests or error responses from the vulnerable endpoint
• Deploy database activity monitoring to detect unusual query patterns or unauthorized data access

Monitoring Recommendations

• Enable detailed logging for the /cp/available.php endpoint and review logs regularly for suspicious activity
• Set up alerts for database errors that may indicate injection attempts
• Monitor network traffic for large data transfers from the database server that could indicate successful data exfiltration
• Implement real-time security monitoring with SentinelOne to detect and respond to exploitation attempts

How to Mitigate CVE-2026-5553

Immediate Actions Required

• Restrict access to /cp/available.php through network-level controls or authentication requirements until a patch is applied
• Implement input validation to allow only expected characters in the Name parameter
• Deploy a Web Application Firewall with SQL injection protection rules
• Consider taking the vulnerable application offline if it processes sensitive data and cannot be immediately patched

Patch Information

No official vendor patch has been identified for this vulnerability. The application is distributed through IT Source Code. Organizations using this software should contact the vendor for remediation guidance or implement the workarounds described below. Additional vulnerability details can be found in VulDB Submission #782873.

Workarounds

• Implement prepared statements with parameterized queries in the /cp/available.php file to prevent SQL injection
• Add input validation to whitelist only alphanumeric characters and expected special characters for the Name parameter
• Deploy a WAF rule to filter malicious input targeting the vulnerable endpoint
• Restrict database user privileges used by the application to limit the impact of successful exploitation

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