CVE-2015-20121: Realtyscript SQLi — Patch Guide

Overview

A high-severity security vulnerability has been identified in Next Click Ventures RealtyScript version 4.0.2. The flaw consists of multiple SQL Injection (SQLi) vulnerabilities that allow unauthenticated attackers to interfere with the application’s database queries. This can lead to the theft of sensitive information or a denial of service.

Vulnerability Details

The vulnerability exists because the software does not properly validate or sanitize user input before using it in database queries. Specifically, attackers can exploit two parameters:

• The u_id parameter in the /admin/users.php page via a GET request.
• The agent[] parameter in the /admin/mailer.php page via a POST request.

By injecting crafted SQL code into these parameters, an attacker can manipulate the database commands the application executes. The vulnerability is of the “blind” type, meaning attackers can use time-delay techniques to extract data piece by piece or cause the system to hang with sleep commands.

Potential Impact

If successfully exploited, this vulnerability can have severe consequences:

• Data Breach: Attackers can extract sensitive information from the database, including user credentials, personal data, and proprietary business information. For insights into the real-world consequences of data theft, you can review historical incidents in our breach reports.
• Denial of Service (DoS): By sending payloads that cause long database delays, attackers can make the application unresponsive to legitimate users.
• Further System Compromise: Extracted data, like administrative passwords, could be used to gain full control of the application or related systems.

Remediation and Mitigation

Primary Action: Update Immediately The most effective remediation is to upgrade RealtyScript to a patched version. Contact Next Click Ventures for information on fixed releases. If a direct patch is not available, consider migrating to a supported alternative.

Immediate Mitigations:

1. Input Validation and Sanitization: Implement strict allow-list input validation for all user-supplied data, particularly the u_id and agent[] parameters. Reject any input that does not conform to an expected format (e.g., only numeric characters for an ID).
2. Use Prepared Statements: Rewrite the database queries in the affected files (/admin/users.php and /admin/mailer.php) to use parameterized queries (prepared statements) with bound variables. This is the most robust defense against SQL injection.
3. Web Application Firewall (WAF): Deploy a WAF in front of the application to help filter out malicious SQL injection payloads. This should be considered a temporary compensating control, not a permanent fix.
4. Restrict Access: If possible, restrict network access to the admin interface to only trusted IP addresses.

Staying informed about such vulnerabilities is crucial for maintaining security. For the latest updates on threats and patches, follow our security news. System administrators should apply these mitigations without delay to protect their systems and data.