CVE-2024-7839: Billing System SQL Injection Vulnerability

CVE-2024-7839 Overview

A critical SQL injection vulnerability has been discovered in itsourcecode Billing System version 1.0. The vulnerability exists in the addbill.php file, where improper handling of the owners_id parameter allows attackers to inject malicious SQL commands. This flaw enables remote attackers to manipulate database queries without authentication, potentially leading to unauthorized data access, modification, or deletion.

Critical Impact

Remote attackers can exploit this SQL injection vulnerability to extract sensitive billing data, modify financial records, or potentially gain complete control over the backend database server.

Affected Products

• itsourcecode Billing System 1.0
• angeljudesuarez billing_system 1.0

Discovery Timeline

• 2024-08-15 - CVE-2024-7839 published to NVD
• 2024-08-19 - Last updated in NVD database

Technical Details for CVE-2024-7839

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) exists in the addbill.php file of the Billing System application. The vulnerable code fails to properly sanitize or parameterize the owners_id input parameter before incorporating it into SQL queries. This allows attackers to craft malicious input that alters the intended SQL query logic.

The vulnerability is exploitable remotely over the network without requiring authentication or user interaction. The exploit has been publicly disclosed, increasing the risk of exploitation in the wild. While the impact is categorized with low confidentiality, integrity, and availability impact, successful exploitation could still allow attackers to read sensitive database records, modify billing information, or cause database errors.

Root Cause

The root cause of this vulnerability is improper input validation and lack of parameterized queries in the addbill.php file. The owners_id parameter is directly concatenated into SQL statements without proper sanitization or use of prepared statements, enabling classic SQL injection attacks. This represents a fundamental secure coding failure where user-supplied input is trusted and used directly in database operations.

Attack Vector

The attack can be initiated remotely over the network by sending specially crafted HTTP requests to the addbill.php endpoint. An attacker can manipulate the owners_id parameter to inject arbitrary SQL commands. The exploitation requires no authentication or special privileges, making it accessible to any remote attacker who can reach the vulnerable application.

Typical attack patterns include:

• Using single quotes to break out of string contexts
• Appending UNION SELECT statements to extract additional data
• Injecting time-based or boolean-based blind SQL injection payloads
• Potentially escalating to stacked queries for data manipulation or command execution

The vulnerability has been publicly documented, with technical details available in the GitHub Issue Discussion and additional tracking information on VulDB.

Detection Methods for CVE-2024-7839

Indicators of Compromise

• Unusual or malformed HTTP requests to addbill.php containing SQL syntax characters such as single quotes, double dashes, or UNION keywords in the owners_id parameter
• Database error messages exposed in HTTP responses indicating SQL syntax errors
• Unexpected database queries or access patterns in database audit logs
• Evidence of data exfiltration or unauthorized modifications to billing records

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns targeting the owners_id parameter
• Implement application-level logging to capture all requests to addbill.php with suspicious parameter values
• Configure database activity monitoring to alert on unusual query patterns or errors originating from the billing application
• Use SentinelOne Singularity XDR to detect post-exploitation activity such as unexpected database connections or data exfiltration attempts

Monitoring Recommendations

• Enable verbose logging on the web server and database to capture request parameters and query execution details
• Set up alerts for HTTP 500 errors or database exception messages originating from billing system endpoints
• Monitor for unusual outbound network traffic from the database server that could indicate data exfiltration
• Review access logs regularly for patterns consistent with automated SQL injection scanning tools

How to Mitigate CVE-2024-7839

Immediate Actions Required

• Restrict network access to the billing system to trusted IP addresses only using firewall rules
• Implement a Web Application Firewall (WAF) to filter SQL injection attempts targeting the owners_id parameter
• Disable the addbill.php functionality if not immediately required for business operations
• Review and audit all database accounts used by the application, ensuring least-privilege access

Patch Information

At the time of publication, no official patch has been released by the vendor for this vulnerability. Organizations should monitor the project repository and VulDB for security updates. In the absence of an official patch, implementing the workarounds below is strongly recommended.

Workarounds

• Modify the addbill.php file to use parameterized queries or prepared statements for all database operations involving user input
• Implement server-side input validation to restrict the owners_id parameter to expected numeric formats only
• Deploy a WAF rule specifically blocking requests containing SQL metacharacters in the owners_id parameter
• Consider replacing the vulnerable billing system with a maintained alternative that follows secure coding practices

# Example WAF rule for ModSecurity to block SQL injection in owners_id
SecRule ARGS:owners_id "@detectSQLi" \
    "id:100001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in owners_id parameter',\
    tag:'CVE-2024-7839'"