Resolve Web Application Service Vulnerabilities

Web Application Service vulnerabilities: Web Service Overflow

This is the most traditional and harmful weakness. The earliest and still widespreadAttackIt comes from the assumption that developers can trust the data input by end users. In fact, this assumption is very dangerous. Our security personnel should maintain a skeptical attitude towards practice. Assume that the user is an attacker. Only in this way can we do a good job in security. However, many developers do not have this security awareness.

Here is a simple example. If a user understands the relevant content of the PowerPoint file format, they can use a text editor to compile a PowerPoint file. Editing is quite simple, but it only makes the data in the internal field more than the data allowed by the system, which will cause the system to crash. Then attackers can execute any program they want to execute. This attack is called an overflow attack. It is applicable to most Web servers.

To put it simply, overflow attacks are caused by putting too much data into the space that the original program designer thinks is sufficient. The extra data overflow will store the package in the nearby memory and overwrite the data irrelevant to the original usage of this region. When other applications are executed, the program uses new data. That is to say, If attackers can use the wrong data to fill up enough space and add malicious code to the data, the application may execute malicious code, to achieve the purpose of the attack. Such as deleting data and updating the website homepage. If the attacked application is started by a system administrator, malicious code may be executed as part of the original program, thus granting the attacker administrator privileges. When attackers obtain administrator privileges, the consequences can be imagined.

For Web Services, pay special attention to buffer overflow attacks. In the buffer overflow attack instance, the internal value of the program will be exceeded, thus changing the running mode of the program. During normal operation of the application, when a function is called, all parameters of the called function and the pointer to the return position will be stored in the memory.

After the job specified by this function is completed, the return pointer will return to the original location and continue executing other programs. This process can be changed by exploiting buffer overflow attacks. That is, let the function execute the program or code that attackers want to execute. You can input enough data to overwrite the original parameters and input new return pointers to different functions.

It can be seen that overflow is critical to Web Services. However, it is not very difficult to make up for this vulnerability. In general, developers only need to do relevant checks during the development process to make up for it. For example, in the text box, perform necessary checks before the user saves the data. Including the data type and whether the data contains special characters that are not allowed. That is to say, when developing Web applications, we should maintain a necessary attitude of doubt to users. Only in this way can we think about how to test user data. After completing this operation, you can avoid overflow attacks to a large extent and improve the security of the application server.

Web Application Service vulnerabilities: SQL injection attacks

The SQL injection attack is a buffer overflow attack. In addition to overflow vulnerabilities, SQL injection is another type of attack that relies on developers not testing input data. For example, most people have character numbers or secrets, or security-conscious people have character digital passwords with other keyboard symbols, which improves the security of passwords. For this security, developers may allow users to enter any character as the password. However, if strict check is not performed during the development process, it may cause SQL injection attacks on the Web server.

The principle of SQL injection attacks is very simple. There are also some technical documents on the Internet. For this reason, I will not elaborate too much here. I just stressed that SQL injection attacks should be paid attention by developers when developing Web applications. Take positive measures to eliminate this weakness.

Based on previous attack cases, we can know that this weakness is one of the most effective attack methods for Web applications. In addition, as you increase your trust in Web applications (such as online transfer and other business applications), their dangers will become greater and greater. In fact, it is easy to prevent this attack. This mainly means that when developing applications, it is necessary to strengthen the detection of user input data. For example, strict restrictions on the length and format of characters entered by users are imposed, and strict checks are performed before the user inputs and saves the data. You only need to check the input to eliminate the security threats caused by this vulnerability.

This article introduces the vulnerabilities of Web application services. We will continue to summarize and share more information with you. Welcome to read: Resolve Web Application Service Vulnerabilities