CVE-2023-41640 is a recently discovered vulnerability affecting GruppoSCAI RealGimm version 1.1.37p38. This flaw resides in how the application handles errors within the ErroreNonGestito.aspx component. By sending specially crafted SQL inputs, an attacker can force the app to spit out detailed internal errors. These errors can reveal technical details about the database and even some of the SQL queries running under the hood. In this post, I’ll break down what this vulnerability is, show you how it works, and walk through a sample exploit.

What’s CVE-2023-41640?

This CVE points to an *improper error handling* issue. When something goes wrong in most web apps, they should show a generic error message to avoid helping attackers figure out how the system works. In this case, RealGimm’s ErroreNonGestito.aspx page returns detailed error messages – including SQL exception details – right in the browser.

Why Is This Dangerous?

Attackers simply need to make the app choke on a crafted SQL input. When that happens, the backend catches the exception and responds with specific information. This is known as *information disclosure* and can be a goldmine in attacks like SQL Injection or recon for more advanced exploits.

Let’s look at an example.

Suppose the vulnerable component accepts a URL parameter called ErrorMessage. When you force it to process something strange — like a lone apostrophe (') — the backend SQL engine gets confused and throws an error.

Here’s a minimal crafted URL

https://vulnerable-server/RealGimm/ErroreNonGestito.aspx?ErrorMessage=';

What happens?

The server processes this, tries to use the ' in a SQL query, and fails. Because of the poor error handling, it returns a page like this:

<html>
<head><title>ErroreNonGestito</title></head>
<body>
  <h1>Errore del server nell'applicazione '/'</h1>
  <p>Descrizione: Eccezione non gestita durante l'esecuzione della richiesta corrente SQL: SELECT * FROM Users WHERE name = ''', Exception: SqlException, LineNumber: 1</p>
  ...
</body>
</html>

Below is *representative* code (not the actual GruppoSCAI source, but commonly used patterns)

try {
    // Dangerous direct concatenation
    string query = "SELECT * FROM Users WHERE name = '" + Request.QueryString["ErrorMessage"] + "'";
    SqlCommand cmd = new SqlCommand(query, conn);
    SqlDataReader dr = cmd.ExecuteReader();
}
catch (Exception ex) {
    Response.Write("Errore del server: " + ex.ToString());
}

What’s wrong:
Instead of logging the error for administrators and showing a safe, generic message, it prints the full exception details to the user.

If an attacker can trigger errors and read server responses, they can

- Map out database structure: Table/column names, query logic, DB engine.

Find vulnerable components: They see where bad input causes problems.

- Ready the way for deeper attacks: Especially SQL Injection, if inputs are not sanitized elsewhere.

Even if this bug doesn’t allow direct exploitation “out of the box,” it makes discovering and weaponizing other weaknesses far easier.

References

- NVD Entry for CVE-2023-41640
- Official Advisory (Italian)
- RealGimm Product Page
- OWASP: Improper Error Handling

Example Safer Error Handler

catch (Exception ex) {
    // Log for admin
    LogException(ex); 
    // Generic message for user
    Response.Write("An unknown error occurred. Please contact support.");
}

Summary

CVE-2023-41640 in GruppoSCAI RealGimm 1.1.37p38 is a classic example of how improper error handling can give attackers everything they need to plan future attacks. Even if there’s no direct SQL Injection, exposing information like database types, table and column names, or stack traces helps attackers map your system. If you’re a RealGimm admin, patch as soon as possible, update your error handling routines, and check your server logs for signs of probing.

If you have more specific questions or want hands-on guidance, drop a comment or inbox me! Stay safe out there.

Timeline

Published on: 08/31/2023 14:15:08 UTC
Last modified on: 09/11/2023 22:15:08 UTC