A recently disclosed vulnerability, CVE-2023-4899, sheds light on a critical security issue within the mintplex-labs/anything-llm GitHub repository, specifically in versions before ..1. This vulnerability—caused by insecure coding practices—opens the door to SQL Injection attacks, which could lead to potentially devastating consequences if exploited by cybercriminals. In this blog post, we will delve into the details of this vulnerability, its root cause, and recommended mitigation strategies.

Vulnerability Overview

SQL Injection (SQLi) is a code injection technique used by attackers to compromise the security of web applications by injecting malicious SQL statements into the input data fields. This can lead to unauthorized access, modification, and even deletion of data within the underlying database.

In the case of CVE-2023-4899, the SQL Injection vulnerability exists in the mintplex-labs/anything-llm repository, which is a project aimed at providing a ready-to-use "Anything" Load, Locate, and Manipulate (LLM) framework. The vulnerability has been introduced in the codebase due to improper input validation and insufficient parameterized query usage, which allows attackers to manipulate database queries and execute arbitrary SQL statements.

The vulnerability specifically affects the following file

- src/login.php

The Issue

In the login.php file of mintplex-labs/anything-llm, the vulnerability can be traced back to the following code snippet where user inputs are not sanitized or parameterized:

$username = $_POST['username'];
$password = $_POST['password'];

$query = "SELECT * FROM users WHERE username='$username' AND password='$password'";
$result = mysqli_query($conn, $query);

In this code snippet, the $username and $password variables are directly taken from the user input, without any sanitation or validation. Consequently, the variables are then included as part of the SQL query, creating a severe risk of SQL Injection.

Proof of Concept (PoC) Exploit

Given the vulnerable code, an attacker could easily attempt SQL Injection by providing a malicious input for the username and password fields:

' OR '1' = '1'; -- '

By including this input, the $query variable will contain the following SQL statement

SELECT * FROM users WHERE username='' OR '1' = '1'; -- '' AND password=''

After executing the query, the SQL statement will return all records from the users table, bypassing any authentication mechanism in place.

Mitigation Strategies

In order to resolve this vulnerability, it is highly recommended to sanitize and validate user inputs. Additionally, parameterized queries should be used instead of directly concatenating user inputs into SQL statements.

Here's a code snippet demonstrating the use of prepared statements with mysqli in PHP

$username = $_POST['username'];
$password = $_POST['password'];

$stmt = $conn->prepare("SELECT * FROM users WHERE username=? AND password=?");
$stmt->bind_param("ss", $username, $password);
$stmt->execute();
$result = $stmt->get_result();

This code ensures that user inputs are properly parameterized, reducing the risk of SQL Injection.

Conclusion

CVE-2023-4899 highlights the importance of secure coding practices, especially when handling user inputs. Developers should be diligent in validating and sanitizing inputs, as well as utilizing parameterized queries. By doing so, they can significantly reduce the likelihood of SQL Injection vulnerabilities, thereby maintaining the security and reliability of their applications.

For more information on this vulnerability, visit the following references

- Original CVE-2023-4899 Advisory
- GitHub Repository of mintplex-labs/anything-llm
- OWASP SQL Injection Prevention Cheat Sheet

Timeline

Published on: 09/12/2023 00:15:00 UTC
Last modified on: 09/13/2023 03:51:00 UTC