Buffer Overflow: Definition, Attacks, Types & More

A buffer overrun, also known as a buffer overflow, happens when the amount of data being stored in the memory buffer exceeds its storage limit. The application overwrites nearby memory locations in the process of trying to copy the data to the buffer. In this article, we will look at buffer overflow attack, types, and Vulnerability

Buffer Overflow

Buffer overflow is a software coding error or vulnerability that can be exploited by hackers to gain unauthorized access to corporate systems. It is one of the best-known software security vulnerabilities, yet it remains fairly common. This is partly because it can occur in various ways, and the techniques used to prevent them are often error-prone.

The software error focuses on buffers, which are sequential sections of computing memory that hold data temporarily as it is transferred between locations. Also known as a buffer overrun, a buffer overflow occurs when the amount of data in the border exceeds its storage capacity. That extra data overflows into adjacent memory locations and corrupts or overwrites the data in those locations.

Buffer Overflow Attack

A buffer overflow attack occurs when a hacker manipulates a coding flaw in order to breach the compromised system and perform harmful actions. The attacker modifies the program’s execution path in order to corrupt already-existing files or disclose data. They also rewrite portions of the application’s memory.

Programming language violations and overwriting buffer boundaries are common components of buffer overflow attacks. Erroneous assumptions regarding the quantity or composition of data, together with memory manipulation, are the main causes of buffer overflows.

How Does a Buffer Overflow Attack Work?

Usually, the attacker combines malicious code with carefully constructed input data to take advantage of software flaws in the targeted system. By manipulating the buffer and causing it to overflow, the malicious code gives the attacker access to run this code.

An attacker must first locate a software program or system that is vulnerable before creating a payload of data that is intended to take advantage of the vulnerability in order to execute a buffer overflow attack. The payload is delivered by a network or web-based attack vector, including phishing websites or emails.

After the payload is received by the target system, the software program is processed and tries to save the incoming data in the buffer. The code will run as intended if the border is too small to hold the data; otherwise, it will overflow.

After taking over the system, the attacker may decide to steal confidential information, interfere with regular business, or access other systems on the network. To stop these attacks, security measures like firewalls and intrusion detection systems must be put in place, along with routine software updates.

Buffer Overflow Attacks in the Past

Let’s examine some well-known instances of buffer attacks from history.

The November 2, 1988, Morris worm, also known as the Internet worm, was one of the first computer worms to garner significant attention from the mainstream media. The Morris worm attack took advantage of multiple vulnerabilities, including UNIX sendmail (using a backdoor), finger (through an exceeding border), and rsh/rexec. It was also able to guess weak passwords. Moreover, it was able to guess weak passwords.
The Sony Pictures Entertainment company suffered a significant breach of its computer systems in November 2014 due to a buffer overflow attack. The attackers stole sensitive data, including unreleased films and the personal information of employees and celebrities.
A buffer overflow attack against Citigroup Bank occurred in June 2011, providing hackers with access to approximately 200,000 customers’ names, addresses, and account numbers. With this information, the attackers were able to pilfer more than $2.7 million from the bank.
In January 2021, the Libgcrypt developers released a security patch update after finding a serious heap-based buffer overflow vulnerability in the program. Attackers could target machines and write any code they wanted thanks to this issue.

Ways to Avoid Buffer Overflows

By including security precautions in their code or by utilizing programming languages with built-in security, developers can guard against buffer overflow vulnerabilities. Runtime protection is another feature of contemporary operating systems. There are three typical safeguards:

To employ the exploitative SEH overwrite method. Functionally, a stack-based buffer overflow is used to overwrite an exception registration record that is kept on the stack of a thread to accomplish an SEH overwrite.
Operating system protection and code security measures alone are insufficient. An organization needs to move fast to fix the impacted software and ensure that users may obtain the patch when they find an overflowing border issue.
Address space randomization (ASLR) shuffles data areas’ address spaces at random. Generally, these attacks require knowledge of the executable code’s location, which is nearly impossible when address spaces are randomly generated.
Data execution prevention prevents an attack from executing code in a non-executable region by marking specific memory locations as executable or non-executable.

Exploits of Buffer Overflow

The operating system and architecture of the target determine the buffer overflow attack strategies a hacker employs. However, the additional information they transmit to software is probably going to contain malicious code, which gives the attacker the ability to launch more commands and initiate more activities.

For instance, adding new code to a program could direct it to do new things, allowing the attacker to get access to the IT systems of the company. An attacker might be able to purposefully enter data that the buffer is unable to contain if they are aware of the memory layout of the program. They will be able to take control by using this to replace executable code stored in memory regions with malicious code.

Buffer Overflow Types

Attackers utilize a variety of buffer overflow techniques to take advantage of systems within companies. The most typical ones are:

#1. Stack-based Buffer Overflows

The most prevalent type of buffer overflow attack is this one. Using the stack-based technique, an attacker can deliver malicious code-containing data to an application, which then saves it in a stack buffer. This gives the attacker control over transfers by overwriting everything on the stack, including the return pointer.

#2. Heap-based Buffer Overflows

It is harder to execute a heap-based attack than a stack-based one. This type of attack entails overflowing a program’s memory beyond what is required for its ongoing runtime functions.

#3. Format String Attack

When an application handles input data as a command or fails to properly check input data, a format string exploit occurs. This type gives the attacker the ability to run code, access data from the stack, and create application segmentation faults. This can set off additional events that jeopardize the system’s stability and security.

Buffer Overflow Vulnerability

Buffer overflows are used by attackers to take control of a machine, execute arbitrary code, and tamper with the execution stack of web applications. Both web servers and application servers may have buffer overflow vulnerabilities, particularly in web applications that make use of libraries like graphics libraries. Coding for vulnerability applications may also contain buffer overflow defects. This is more likely because they are harder to exploit, less likely to be found by hackers and receive less attention from security professionals.

A buffer overflow vulnerability will typically occur when code:

Is reliant on external data to control its behavior
Is dependent on data properties that are enforced beyond its immediate scope
Is so complex that programmers are not able to predict its behavior accurately

Consequences of Buffer Overflow

The following are typical outcomes of a buffer overflow attack:

System crashes: Usually, this attack causes the system to crash. It might also cause programs to enter an endless cycle and cause a lack of availability.
Loss of access control: This attack frequently uses arbitrary code, which is frequently outside the parameters of security regulations in applications.
Additional security concerns: An attacker may use this attack that leads to arbitrary code execution to break into other systems and compromise other security measures.

What Is an Example of a Buffer Overflow?

For instance, code that depends on external data and uses the ‘gets()’ function to get data from a stack buffer may result in a straightforward buffer overflow. Users must input fewer characters than ‘BUFSIZE’ in order to ensure code safety, as the system is unable to restrict the amount of data that the function can read.

Is Buffer Overflow a Ddos Attack?

The most typical kind of DDoS assault is a buffer overflow attack. Though some programming languages are more vulnerable than others, they affect almost all apps and web servers.

What Causes a Buffer Overflow?

What Does status_stack_buffer_overrun Mean?

Although at first it implied that there had been a stack buffer overrun, I have pointed out previously that STATUS_STACK_BUFFER_OVERRUN doesn’t necessarily indicate that. It was too late to rename the status code when it was later expanded to imply “Program self-triggered abnormal termination.”

What Tools Are Used to Detect Buffer Overflow?

They may verify your code either before or after it is executed because they are either static or dynamic. Tools for detecting exceeding border include Fuzzing, AddressSanitizer, and Valgrind.

Which Debugger Is Best for Buffer Overflow?

For instance, you can examine your program’s memory layout, registers, stack, and heap using a debugger like gdb, lldb, or Visual Studio Debugger. To find and report memory issues, you can also use a memory debugger such as Dr. Memory, AddressSanitizer, or Valgrind.

Buffer Overflow: Definition, Attacks, Types & More

Table of Contents Hide

Buffer Overflow