SQL security vulnerabilities mainly include SQL injection, unsafe configuration, improper permission management and missing logs. The prevention measures are: use parameterized query, strict input verification, and minimum permission principles; restrict access to IP, modify default accounts, and regularly update versions; allocate permissions for independent accounts, manage by role, and regularly audit permissions; enable audit logs, centralized storage, and set alarms.

SQL security vulnerabilities are one of the most common risks in many application systems, especially those that rely on databases for data storage and query. Once these vulnerabilities are exploited, they may lead to data breaches, tampering and even deletion. The most common problem is SQL injection attacks, but there are other security risks that are easily overlooked. The following is analyzing these vulnerabilities and response methods from several common perspectives.

SQL Injection: The Most Classic and Dangerous Vulnerability

SQL injection refers to an attacker using malicious SQL statements to bypass application logic and directly operates the database by inserting malicious SQL statements into the input. For example, entering the username ' OR '1'='1 in the login interface may skip password verification and log in directly.

Precautionary advice:

• Use parameterized queries (also called precompiled statements), instead of splicing strings.
• Strictly filter and verify user input, such as the whitelisting mechanism.
• The principle of minimum permissions ensures that the database account has no unnecessary permissions.
• Do not expose the database structure for error messages, and return a general error message uniformly.

The reason why this type of vulnerability is that SQL statements may be spliced directly for convenience during development, especially during rapid development or legacy system maintenance.

Unsecure database configuration

The database installed by default often does not have sufficient security reinforcement, such as opening unnecessary ports, using default account name and password, and not turning off debug mode.

Frequently asked questions include:

• Database monitoring is on 0.0.0.0, and is completely open to the external network
• No strong password is set for root or SA account
• The database version is not updated regularly, and there are known vulnerabilities

Solution:

• Restrict database access to IP and allow only specific application server connections
• Modify the default account name, set a complex password, and disable unwanted accounts
• Regularly check and close unused functions and services (such as remote access, log output, etc.)

Although this type of configuration problem seems simple, it is often overlooked in actual deployment, especially in small projects or test environments.

Improper permission management leads to horizontal penetration

In many systems, the database user permission settings are too loose, for example, an ordinary user's database account has advanced permissions such as creating tables and executing commands.

Typical manifestations:

• There are multiple applications in the same database that share one account
• The account has high-risk permissions such as DROP , DELETE , and EXECUTE
• There is no role-based permission control mechanism

Improvement method:

• Each application uses an independent account, and the minimum permissions are allocated.
• Use the role management function of the database to divide permission groups by business
• Regularly audit permission changes records to prevent permission inflation

This problem is often not considered clearly in the early design stage of the system, and the later modification is expensive, so the authority system should be planned from the beginning.

Logs and monitoring are missing, making it difficult to track attacks

Many systems only find that there is no valid log record after an accident, or that the log storage time is too short to restore the attack process.

Suggested measures:

• Turn on the database audit log to record all SQL execution statements and operation users
• Store logs centrally to avoid local deletion or overwriting
• Setting out abnormal behavior alarms, such as a large number of queries, sensitive table access in a short period of time, etc.

The log itself does not prevent attacks, but is very critical in post-analysis and traceability. For systems with high compliance requirements, audit logs and even must-have items.

Basically, these common SQL security issues and response methods are all about. Most of them are not particularly complex technical problems, but they are easily overlooked in actual development and operation and maintenance. With just a little more thought during the design and deployment phase, the potential risks can be greatly reduced.

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