Types of Application Attacks: Top 5 You Need to Know

It’s no surprise that cybercriminals often target the applications we use every day. Applications are everywhere—powering websites, mobile apps, and business platforms. Because they handle sensitive data and connect to networks, they’re a favorite entry point for attackers.

Unfortunately, applications have a wide variety of vulnerabilities that can be exploited. These weaknesses can allow threat actors to gain unauthorized access, steal information, or disrupt services.

In this article, we’ll cover five of the most common types of application attacks:

Cross-Site Scripting (XSS)

SQL Injection

Directory Traversal

Buffer Overflow

API Attacks

Let’s break them down.

1. Cross-Site Scripting (XSS)

Cross-site scripting (XSS) occurs when a malicious script is injected into a website that is trusted. Attackers might embed the code in a URL, form, or comment field.

When unsuspecting users visit the site, the browser executes the malicious script, allowing the attacker to:

• Steal cookies or session tokens
• Redirect users to harmful websites 
• Bypass security controls

XSS attacks are hazardous because they compromise the trust between users and legitimate applications.

2. SQL Injection

SQL injection (SQLi) is one of the most well-known application attacks. It happens when an attacker inserts malicious SQL code into an input field, tricking the database into revealing, modifying, or deleting information.

For example, poorly secured login forms may allow attackers to bypass authentication or dump sensitive user data. 

This type of attack underscores the importance of input validation and parameterized queries as critical safeguards in web development.

3. Directory Traversal

A directory traversal attack (sometimes called path traversal) takes advantage of insecure file path handling in applications.

By manipulating input (such as a URL or form field), attackers can access files and directories outside the intended web root. This can expose: 

• System configuration files 
• Sensitive data
• Credentials or source code

Directory traversal is often used as a stepping stone to compromise a system further. 

4. Buffer Overflow

A buffer overflow occurs when an application writes more data to a memory buffer than it can handle. The overflow allows attackers to overwrite adjacent memory, potentially causing the system to crash or inject malicious code.

While buffer overflows are an older attack technique, they remain relevant—especially in software written in low-level programming languages like C or C++. Exploiting them can give attackers the ability to execute arbitrary code and take control of a system.

5. API Attacks

Modern applications often rely on Application Programming Interfaces (APIs) to connect services and exchange data. When APIs aren’t secured, attackers can exploit them to:

• Steal sensitive information
• Manipulate data
• Disrupt services

Since APIs are increasingly central to mobile apps, cloud services, and IoT devices, they’ve become a top target for attackers. Poor authentication, weak encryption, and excessive data exposure are common weaknesses.

Final Thoughts

Application attacks are among the most common and damaging cybersecurity threats today. From stealing personal information to crashing entire systems, attackers exploit weaknesses in the software we rely on daily.

The good news? By understanding these vulnerabilities, both developers and security professionals can better defend against them. Implementing secure coding practices, conducting regular vulnerability assessments, and utilizing robust monitoring tools are crucial steps in maintaining application security.

👉 Want to learn more about defensive strategies? Check out our post on Defense in Depth: What It Is and Why You Need It