Privilege Limitations in Cloud

Context

In this article, we will explore the concept of privilege limitations within MariaDB, particularly as implemented in cloud environments. Understanding these restrictions is crucial for identifying and exploiting potential vulnerabilities when conducting offensive security assessments. To get the most out of this guide, you should already be familiar with cloud service models, database privileges, and SQL query execution.

Theory

Cloud Privilege Hardening

Cloud providers strive to enhance the security of database systems by implementing privilege restrictions as part of their cloud services. A core element of this strategy is enforcing the least privilege principle. This principle ensures that each user has the minimum level of access required to perform their tasks, effectively minimizing the attack surface. However, vulnerabilities can surface through misconfigured privileges, which may open pathways for exploitation.

MariaDB Privilege Limitations in Cloud

MariaDB databases hosted in cloud environments often have certain SQL operations restricted to prevent misuse. Commonly restricted operations include:

• DROP: Dropping databases or tables might be disallowed to prevent accidental data loss or malicious activity.
• SUPER Privilege: Critical administrative operations requiring the SUPER privilege are often blocked.
• File Access: Reading files from the server's filesystem is generally prohibited to safeguard sensitive data.

Such limitations form a vulnerability model that can be exploited if there are misconfigurations in the privilege settings. Attackers may take advantage of these misconfigurations to perform unauthorized actions.

Impact of Privilege Limitations

Privilege limitations are designed to prevent unauthorized data manipulation and ensure the integrity of the database. However, attackers may attempt to bypass these restrictions to gain unauthorized access or escalate privileges. Understanding and identifying these limitations is an essential step in executing successful privilege escalation strategies during security assessments.

Practice

Exploiting Misconfigured Privileges in Cloud MariaDB

To assess and potentially exploit privilege misconfigurations in a cloud-hosted MariaDB, follow these steps:

• Check Misconfigured Root Privileges:

  SELECT * FROM mysql.user WHERE user='root';
  

  Use this command to inspect the privileges granted to the root user. Misconfigurations in these privileges could be leveraged for escalation.

• Identify User Privileges:

  SHOW GRANTS FOR 'user'@'host';
  

  This step helps identify the specific privileges granted to a user, which could reveal excessive or inappropriate permissions.

• Test File Access Restrictions:

  SELECT LOAD_FILE('/etc/passwd');
  

  Attempt to access restricted files to check if there are unintended allowances in file permission settings that could be exploited.

• Test DROP Privilege Restrictions:

  DROP DATABASE test_db;
  

  Execute this command to verify whether DROP privileges are erroneously assigned, allowing potential data manipulation or destruction.

By following these steps, a skilled security professional can identify and exploit privilege misconfigurations, potentially gaining unauthorized access or achieving privilege escalation.

Tools

• MySQL Client
• SQLMap