Overview
This blog post delves into the details of the recently discovered CVE-2025-26186, a SQL Injection vulnerability in openSIS v.9.1. This vulnerability is significant because it allows an attacker to execute arbitrary code remotely via the id parameter in Ajax.php. This has an alarming potential impact on the system including compromise and data leakage, affecting all users or systems that employ openSIS v.9.1. The severity and widespread use of this software make understanding and resolving this vulnerability critical.
Vulnerability Summary
CVE ID: CVE-2025-26186
Severity: High (CVSS: 8.1)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage
Affected Products
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Product | Affected Versions
openSIS | v.9.1
How the Exploit Works
This vulnerability stems from unchecked or improperly sanitized user input in the ‘id’ parameter of the Ajax.php file. An attacker can exploit this by injecting malicious SQL code into this parameter. This malicious SQL code is then processed by the server, leading to unauthorized execution of arbitrary code. This arbitrary code execution can lead to actions such as unauthorized data access, data manipulation, or additional malicious activity.
Conceptual Example Code
The following conceptual code illustrates how an attacker may exploit this vulnerability. This is not an actual exploit code but serves to provide a basic understanding of the exploit mechanism.
POST /Ajax.php HTTP/1.1
Host: vulnerable-opensis.example.com
Content-Type: application/x-www-form-urlencoded
id=1'; DROP TABLE students; --In this conceptual example, the attacker manipulates the ‘id’ parameter to inject a SQL command to drop the ‘students’ table from the database. Note the use of ‘ — ‘ to comment out the rest of the legitimate SQL query, ensuring only the injected code is executed.
Mitigation Guidance
The primary mitigation strategy for this vulnerability is to apply the vendor’s patch for openSIS v.9.1. If this is not immediately possible, a temporary measure could be to implement a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to monitor and block suspicious activity. However, these temporary measures do not remove the vulnerability and should only be used until the patch can be applied. Regularly updating and patching software is the best defense against such vulnerabilities.
In addition, developers should always sanitize user input to prevent SQL Injection attacks and adhere to the principle of least privilege when designing and implementing software to limit the potential impact of such vulnerabilities.