CVE-2019-25501: Simplejobscript SQL Injection Vulnerability

CVE-2019-25501 Overview

Simple Job Script contains an SQL injection vulnerability that allows attackers to manipulate database queries by injecting malicious SQL code through the app_id parameter. Attackers can send POST requests to delete_application_ajax.php with crafted payloads to extract sensitive data, bypass authentication, or modify database contents. This vulnerability poses a significant risk to organizations using Simple Job Script as it enables unauthorized access to backend databases.

Critical Impact

Attackers can exploit this SQL injection vulnerability to extract sensitive data from the database, bypass authentication mechanisms, or modify database contents through malicious payloads sent to the delete_application_ajax.php endpoint.

Affected Products

• Simple Job Script (all versions)

Discovery Timeline

• 2026-03-04 - CVE-2019-25501 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2019-25501

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) exists in the Simple Job Script application within the delete_application_ajax.php endpoint. The vulnerability occurs because user-supplied input through the app_id parameter is not properly sanitized before being incorporated into SQL queries. This allows an attacker to inject arbitrary SQL commands that the database will execute with the same privileges as the application.

The attack surface is network-accessible, meaning remote attackers can exploit this vulnerability without requiring authentication or user interaction. The primary impact is on data confidentiality, as attackers can extract sensitive information from the database. Additionally, there is potential for limited data integrity impact through database modification.

Root Cause

The root cause of this vulnerability is improper input validation and lack of parameterized queries in the delete_application_ajax.php file. The application directly concatenates user input from the app_id POST parameter into SQL query strings without proper sanitization or escaping. This classic SQL injection pattern allows attackers to break out of the intended query structure and inject their own SQL commands.

Attack Vector

The vulnerability is exploited by sending specially crafted POST requests to the delete_application_ajax.php endpoint. An attacker constructs a malicious payload in the app_id parameter that terminates the original SQL query and appends additional SQL statements. These injected commands can perform various malicious operations including:

• Extracting sensitive data using UNION-based or error-based SQL injection techniques
• Bypassing authentication by manipulating query logic
• Modifying or deleting database records
• Potentially escalating to remote code execution if database permissions allow file operations

The vulnerability can be exploited by crafting a POST request to the vulnerable endpoint with a payload in the app_id parameter. For example, an attacker might use time-based blind SQL injection or UNION-based techniques to enumerate database contents. Detailed technical information about exploitation techniques can be found in the Exploit-DB #46612 entry.

Detection Methods for CVE-2019-25501

Indicators of Compromise

• Unusual POST requests to delete_application_ajax.php containing SQL syntax characters such as single quotes, double dashes, or UNION keywords in the app_id parameter
• Database error messages appearing in web server logs indicating malformed SQL queries
• Unexpected database queries or access patterns in database audit logs
• Evidence of data exfiltration or unauthorized database modifications

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block SQL injection patterns in POST requests targeting delete_application_ajax.php
• Configure intrusion detection systems (IDS) to alert on requests containing common SQL injection signatures such as ' OR '1'='1, UNION SELECT, or -- comment sequences
• Enable detailed logging on web servers and databases to capture suspicious parameter values and query execution patterns
• Deploy application security monitoring to detect anomalous database query behavior

Monitoring Recommendations

• Monitor web server access logs for requests to delete_application_ajax.php with abnormally long or encoded app_id parameter values
• Set up alerts for database errors that may indicate SQL injection attempts such as syntax errors or unexpected query terminations
• Review database audit logs regularly for signs of data exfiltration or unauthorized access patterns
• Implement real-time security monitoring for applications running Simple Job Script

How to Mitigate CVE-2019-25501

Immediate Actions Required

• Immediately restrict access to the delete_application_ajax.php endpoint through web server configuration or firewall rules
• Implement input validation to reject any app_id values containing non-numeric characters
• Consider disabling the affected functionality until a proper fix can be implemented
• Review database logs for evidence of prior exploitation and assess potential data exposure

Patch Information

No vendor patch information is currently available for this vulnerability. Organizations using Simple Job Script should consider implementing the workarounds below or migrating to an alternative solution. Monitor the VulnCheck Advisory for updates on remediation guidance.

Workarounds

• Modify the delete_application_ajax.php file to use parameterized queries or prepared statements instead of direct string concatenation
• Implement strict input validation to ensure the app_id parameter contains only numeric values using server-side validation
• Deploy a web application firewall (WAF) configured to detect and block SQL injection attempts targeting this endpoint
• Restrict network access to the administrative functions of Simple Job Script to trusted IP addresses only

# Example Apache configuration to restrict access to vulnerable endpoint
<Location "/delete_application_ajax.php">
    Order Deny,Allow
    Deny from all
    Allow from 192.168.1.0/24
</Location>