Avoid backdoor attack points left in PHP language development

With the popularity of the Internet and the rapid development of Web applications, the security issues of Web applications have become more and more important. Among them, more than 90% of web application implementations are completed through the PHP language. However, the PHP language itself has many security vulnerabilities. These vulnerabilities, when exploited by hackers, can lead to backdoor attacks on web applications, making user information and data no longer safe. Therefore, we must be aware of avoiding legacy backdoor attack points in PHP language development. importance.

As a simple and easy-to-use language, PHP language's architecture based on modular development also allows developers to develop more efficiently based on its rich resource library. However, due to the openness of the PHP language and the openness of the underlying ecosystem, it also has some security vulnerabilities that need to be paid attention to, such as SQL injection, file inclusion, remote code execution, etc.

1. SQL injection

In web system development, SQL injection is one of the most common security vulnerabilities. The reason is that web applications usually need to obtain data from the database, insert data into the database, and update data, and these operations require the use of SQL statements. SQL injection attacks are performed by adding malicious SQL statements to web forms or submission requests to bypass the application's verification and filtering mechanisms, thereby conducting malicious attacks on the database. Such attacks may lead to data leakage, data changes, system paralysis and other consequences.

Precautionary measures:

• Use parameterized queries instead of string concatenation to construct SQL statements
• Strict filtering and verification of user input, such as escaping Special characters, limited input length, etc.
• Restrict the permissions of database users to avoid granting unnecessary operation permissions

2. Files contain

files Containment vulnerabilities are an attack in which hackers gain system access by injecting dangerous code into a web application. This attack usually achieves the purpose of the attack by allowing the application to contain files with security vulnerabilities and then execute malicious code.

Precautions:

• Check and verify all file inclusion operations to avoid path inclusion vulnerabilities
• Strictly separate application code and user uploaded files
• Set folder permissions appropriately to prevent files from being accessed by unauthorized users

3. Remote code execution

Remote code execution vulnerability is a very serious security issue problem, it is usually caused by an application improperly calling remote procedure calls (RPC) or operating system command execution (Exec and System). Hackers often exploit system vulnerabilities, send their own malicious code to a remote server, and then trick users into accessing the application to execute the malicious code.

Precautionary measures:

• Strengthen the filtering and verification of user input, and restrict untrusted parameters
• Disable dangerous PHP functions, filters and parameters
• Avoid using executable code, such as eval, assert, system, etc.

In summary, it is very important to avoid leaving backdoor attack points in PHP language development, because once The consequences of being attacked are disastrous. We need to strengthen developers' security awareness and capabilities and take effective measures to prevent and prevent the occurrence of various security vulnerabilities. Only in this way can we ensure the security of user data and the robust operation of web applications on the network.

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