Developer’s Guide to Web Application Security

When it comes to security, there are many vulnerabilities that can leave your website or web app open to attack. In this article, we’ll go over 15 common web application security vulnerabilities and how you can prevent them.

1. Insufficient Cryptography

Cryptography is a critical security measure that is used to protect data in transit and at rest. Yet, many web applications do not use cryptography properly, leading to a number of serious vulnerabilities including potentially devastating code theft. For example, data can be easily intercepted and read if it is not properly encrypted or encryption keys can be easily guessed or stolen if they are not properly protected.

To properly protect data, it is important to use strong cryptography. This includes using proper encryption algorithms, encrypting data in transit and at rest, properly protecting encryption keys and more. It is also important to keep all software up-to-date, as new cryptography vulnerabilities are constantly being discovered.

2. Broken Access Control

Access control is a security measure that controls who has access to what data and functionality in a system. It is an important part of any web application but often is not implemented correctly. This can lead to serious vulnerabilities such as sensitive data being leaked or attackers gaining access to administrative features.

There are a number of common mistakes that can lead to broken access control, such as failing to properly restrict access to data and functionality, using insecure methods for storing and transmitting user credentials and not properly protecting session tokens. In order to prevent these kinds of vulnerabilities, it is important to implement proper access control measures in your web application.

3. Broken Authentication and Session Management

Authentication and session management are two of the most important security measures in any web application. Yet, they are very often not implemented correctly, leading to a number of serious vulnerabilities. For example, session ID’s can be easily guessed or stolen, cookies can be tampered with and passwords can be brute-forced.

In order to properly protect user data and prevent these kinds of vulnerabilities, it is important to implement strong authentication and session management mechanisms. This includes using strong passwords, two-factor authentication, proper session expiration and invalidation, and more. It also means properly protecting any session IDs and cookies that are used by the application.

4. Cross-Site Scripting

Cross-site scripting (XSS) is a type of vulnerability that allows an attacker to inject malicious code into a web page. This can be used to steal data, hijack sessions, redirect users to malicious sites and more. XSS is one of the most common web application vulnerabilities, especially in our era of remote work. Despite security awareness training, many employees remain vulnerable to social engineering and phishing tactics when these risks are not properly addressed.

To protect against XSS attacks, it is important to sanitize all user input and output. This includes properly escaping special characters, using a whitelist of allowed characters and more. It is also important to keep all software up-to-date as new XSS vulnerabilities are constantly being discovered.

5. Insecure Direct Object References

Insecure direct object references (IDOR) are a type of vulnerability that allows an attacker to directly access data that they should not have access to. For instance, an attacker could guess or brute-force the URL of a sensitive file, such as a customer’s credit card information, and then download it. IDORs can also be used to bypass security measures such as access control checks.

In order to prevent IDOR vulnerabilities, it is important to properly validate all user input and restrict access to data and functionality to only those who are supposed to have access to it. It is also important to keep all software up-to-date as new IDOR vulnerabilities are constantly being discovered.

6. Insufficient Authorization and Authentication

Insufficient authorization and authentication is a type of vulnerability that allows an attacker to gain access to data or functionality that they should not have access to. This can be due to a number of factors, such as weak passwords, improperly implemented role-based access control, deliberate over-permissioning and more.

To properly protect data and prevent these kinds of vulnerabilities, it is important to implement strong authentication and authorization mechanisms. This includes using strong passwords, two-factor authentication (2FA), proper role-based access control and more. It is also important to keep all software up-to-date as new vulnerabilities are constantly being discovered.

7. Failure to Restrict URL Access

Another common web application security vulnerability is the failure to restrict URL access. This can allow attackers to gain access to sensitive data or functionality that they should not have.

One of the most common problems developers face is forgetting to properly restrict access to directories and files. For example, they may forget to add an index.html file to a directory. This oversight would give anyone who accesses that full directory read and write access to all the files in it.

Another common issue is that developers do not properly restrict access to certain URL parameters. For example, they may allow anyone to access the “id” parameter, which could be used to view or modify data that they should not have access to.

To prevent these kinds of vulnerabilities, it is important to make sure that all directories and files are properly restricted and that all URL parameters are properly sanitized before being used.

8. Remote File Inclusion

Remote file inclusion (RFI) is a type of vulnerability that allows an attacker to include a remote file, usually through a script or other type of application, on a vulnerable web page. This can be used to inject malicious code into the page which can then be executed by anyone who views it.

One of the most common problems with RFI is that developers do not properly sanitize user input, which allows attackers to inject their own files into the page. Another issue is that developers often use static include paths which makes it easy for attackers to guess the path and inject their own files.

To limit these kinds of vulnerabilities, it is important to make sure that all user input is properly sanitized and that dynamic include paths are used.

9. Insufficient Logging and Monitoring

Logging and monitoring are critical security measures that are used to detect and respond to security incidents. Despite these critically important functions, many web applications do not properly log and monitor activity, leading to a number of serious vulnerabilities. For example, an attacker could easily cover their tracks or an incident could go undetected if there is not proper monitoring in place.

In order to properly detect and respond to security incidents, it is important to properly log and monitor activity. This includes logging all activity, monitoring for suspicious activity and more. It is also important to keep all software up-to-date, as new logging and monitoring vulnerabilities are constantly being discovered.

10. Security Misconfiguration

Security misconfiguration is a type of vulnerability that arises when a web application is not properly configured. This can lead to a number of serious security issues such as exposing sensitive data, making it easier for attackers to gain access to systems, and more.

To mitigate risk when it comes to these kinds of vulnerabilities, it is important to properly configure all software and systems. This includes setting strong passwords, disabling unnecessary accounts and services, properly configuring firewalls and more. It is also important to keep all software up-to-date as new security misconfiguration vulnerabilities are constantly being discovered.

11. Tampering with Data

Data tampering occurs when an attacker tries to modify data without permission. This can end up having a number of serious consequences, such as corruption of data, loss of data integrity and more.

To prevent data tampering, it is important to properly protect data through data handling and storage best practices. This includes using proper authentication and authorization mechanisms, encrypting data in transit and at rest, properly protecting encryption keys and more. It is also important to keep all software up-to-date as new data tampering vulnerabilities are constantly being discovered.

12. Cross-Site Request Forgery (CSRF)

Cross-site request forgery (CSRF) is a type of vulnerability that allows an attacker to trick a user into submitting a malicious request. The goal is to be granted requests to do things without the user’s knowledge or consent, such as changing their password, transferring funds and more.

To prevent CSRF attacks, it is important to properly validate all requests. This includes using proper request validation mechanisms, such as checking for a valid CSRF token, 2FA and more.

Be Aware of Vulnerabilities

We use and rely on a large number of web apps in our daily and commercial lives. While most of these apps are relatively safe and secure, there are still a number of common security vulnerabilities that can leave them open to attack.

To keep your web apps safe and secure, it is important to be aware of these vulnerabilities and know how to prevent them. This includes keeping all software up-to-date, using proper authentication and authorization mechanisms, encrypting data in transit and at rest and training users to identify social engineering and phishing attempts, among others. By following these best practices, you can help to ensure that your web apps are as safe and secure as possible.