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Stack-Based Buffer Overflows on Windows x86

This module is your first step into Windows Binary Exploitation, and it will teach you how to exploit local and remote buffer overflow vulnerabilities on Windows machines.

4.87

Created by 21y4d

Medium Offensive

Summary

Windows binary exploitation has advanced throughout the years, from basic stack overflow techniques to advanced security bypass techniques and heap exploitation. To reach a level of understanding that enables us to successfully exploit even the most advanced applications, we must have a firm grasp of the fundamentals of Windows binary exploitation, which is the main aim of this module.

The Stack-Based Buffer Overflows on Windows x86 module is your first step in Windows Binary Exploitation, and it will take you through the following:

  1. What is binary exploitation and buffer overflows
  2. How to debug Windows programs
  3. Basics of local and remote fuzzing of Windows programs
  4. Finding and using return instructions to subvert the program execution flow
  5. Crafting malicious payloads and scripts to gain local and remote control through buffer overflow vulnerabilities
  6. Developing a functional multi-tier Python exploit for stack-based buffer overflows, which can be used as a basis for other buffer overflow exercises

Throughout the module, we will be attacking two different programs. First, we will generate a malicious .wav file that exploits a buffer overflow vulnerability in an audio converter to perform local privilege escalation. Then, we will move towards remote exploitation by attacking a remote server to gain remote code execution over it after debugging the vulnerable binary locally and developing an exploit.

In addition to teaching the above topics, this module will also cover:

  • A short history of stack-based buffer overflows, and real-world examples of these vulnerabilities
  • The process behind developing a stack-based buffer overflow
  • Fuzzing a program's fields and parameters
  • Identifying the exact offset of our input's location within the buffer
  • Controlling the address of the return instruction
  • Identifying and eliminating potentially bad characters from our exploit
  • Learning multiple methods of finding and utilizing return instructions to subvert execution flow
  • Generating shellcodes and executing them through our return instructions
  • Fuzzing a listening port gradually to identify the length of its buffer precisely
  • Adapting our local exploit to attack remote ports

CREST CPSA/CRT-related Sections:

  • All sections

CREST CCT INF-related Sections:

  • All sections

This module is broken down into sections with accompanying hands-on exercises to practice each of the tactics and techniques we cover.
The module ends with a practical hands-on skills assessment to gauge your understanding of the various topic areas.

As you work through the module, you will see example commands and command output for the various topics introduced. It is worth reproducing as many examples as possible to reinforce further the concepts presented in each section. You can do this in the PwnBox provided in the interactive sections or your virtual machine.

You can start and stop the module at any time and pick up where you left off. There is no time limit or "grading," but you must complete all of the exercises and the skills assessment to receive the maximum number of cubes and have this module marked as complete in any paths you have chosen.

The module is classified as "Medium" and assumes a working knowledge of the Windows command line and an understanding of information security fundamentals.

This module assumes a basic understanding of computer, processor, and memory architecture and will build on this understanding to teach how stack-based buffer overflows work. Therefore, we strongly recommended finishing the Intro to Assembly Language module before starting this one to easily grasp all of the concepts taught in this module and learn the basics necessary for binary exploitation. Also, as this module also teaches the basics of building a Python exploit, the Introduction to Python 3 should help.

In addition to the above, a firm grasp of the following modules can be considered prerequisites for successful completion of this module:

  • Learning Process
  • Windows Fundamentals
  • Introduction to Python 3
  • Intro to Assembly Language

Buffer Overflow


Binary exploitation is among the most essential skills for any pentester. It is usually the way to find the most advanced vulnerabilities in programs and operating systems and requires a lot of skill. Over the years, many protections have been added to the way memory is handled by the OS Kernel and how binaries are compiled to prevent such vulnerabilities. Still, there are always newer ways to exploit minor mistakes found in binaries and utilize them to gain control over a remote machine or gain higher privilege over a local machine.

As binary and memory protections become more advanced, however, so do the binary exploitation methods. This is why modern binary exploitation methods require a deep understanding of Assembly language, Computer Architecture, and the fundamentals of binary exploitation.

Both Assembly language and Computer Architecture were thoroughly covered in the Intro to Assembly Language module, and the Stack-Based Buffer Overflows on Linux x86 module also covered basics of binary exploitation on Linux.


Buffer Overflows

In Binary exploitation, our primary goal is to subvert the binary's execution in a way that benefits us. Buffer Overflows are the most common type of binary exploitation, but other types of binary exploitation exist, such as Format String exploitation and Heap Exploitation.

A buffer overflow occurs when a program receives data that is longer than expected, such that it overwrites the entire buffer memory space on the stack. This can overwrite the next Instruction Pointer EIP (or RIP in x86_64), which causes the program to crash because it will attempt to execute instructions at an invalid memory address. By forcing the program to crash, this is the most basic example of exploiting buffer overflows - known as a Denial of Service (DOS) attack.

Another basic attack is to overwrite a value on the stack to change the program's behavior. For example, if an exam program had a buffer overflow vulnerability, we can overwrite the buffer enough to overwrite our score. Since our exam score is stored in the stack in this example, we could take advantage of this flaw to change our score.

If we are a bit more sophisticated, we can change the address of EIP to an instruction that will execute our shellcode. This would allow us to execute any command we want instead of just crashing the program, known as Jumping to Shellcode.

With more advanced memory protections, it may not be possible to load our entire shellcode and point to it. Instead, we may use a combination of instructions from the binary to execute a particular function and overwrite various pointers to change the program execution flow. This is known as Return Oriented Programming (ROP) attacks.

Finally, modern programs and operating systems may use the Heap instead of the Stack to store buffer memory, which would require Heap Overflows or Heap Exploitation methods.


Stack Overflow

Let's start by demonstrating how the stack works in storing data. The stack has a Last-in, First-out (LIFO) design, which means we can only pop out the last element pushed into the stack. If we push an item into the stack, it would be located on the top of the stack. If we pop anything from the stack, the item located at the top of the stack would get popped.

The following table demonstrates how the stack works. We can click on push to push a value from eax to the stack, and pop to pop the top value from the stack into eax:

0xabcdef <-- Top of Stack ($esp)
0x12345678 <-- Bottom of Stack ($ebp)
eax:




The above example correctly receives buffer data, such that it never gets overflowed to the next item. Now let's review another example that does not correctly store data on the stack.

The following example expects an input from us that is eight characters long. But what would happen if we sent something longer? Let's try to send '01234567890123456789':

0xabcdef <-- Top of Stack ($esp)
0x401000 <-- Return Address ($eip)
0x12345678 <-- Bottom of Stack ($ebp)
eax:




As we can see, when we send a string that is longer than expected, it overwrites other existing values on the stack and would even overwrite the entire stack if it is long enough. Most importantly, we see that it overwrote the value at EIP, and when the function tries to return to this address, the program will crash since this address '0x6789' does not exist in memory. This happens because of the LIFO design of the stack, which grows upwards, while a long string overflows values downwards until it eventually overwrites the return address EIP and the bottom of the stack pointer EBP. This was explained in the Intro to Assembly Language module.

Whenever a function is called, a new stack frame is created, and the old EIP address gets pushed to the top of the new stack frame, so the program knows where to return once the function is finished. For example, if our buffer input overwrites the entire stack and return address EIP, then the overwritten EIP address will be called when the function returns due to a RET instruction.

If we calculate our input precisely, we can place a valid address in the location where EIP is stored. This would lead the program to go to our overwritten address when it returns and subvert the program execution flow to an address of our choosing.


Real-World Examples

There have been numerous incidents where stack overflow exploits were used to break into restricted systems, like mobile phones or gaming consoles.

In 2010, iPhones running on iOS 4 were jailbroken using the greenpois0n jailbreak, which utilized two different exploits to gain kernel-level access over the iPhone and install unofficial/unsigned software and apps. One of these exploits was a stack-based buffer overflow on the iPhone's HFS Volume Name. At that time, iPhones did not automatically randomize the address space, and iOS 4.3 patched these vulnerabilities and introduced memory protections like randomizing address spaces with Address Space Layout Randomization (ASLR).

A stack-based buffer overflow exploit was also used to gain kernel-level access on the original PlayStation Portable (PSP) running Firmware v2.0. This allowed the use of pirated games as well as installing unsigned software. The TIFF Exploit exploits a vulnerability found in the TIFF image library used in the PSP's photo viewer. This leads to code execution by simply viewing a malicious .tiff file in the photo viewer after setting the background to a corrupt .png image. Another similar stack overflow exploit was later discovered in the PSP game "Grand Theft Auto: Liberty City Stories", which had an overflow vulnerability in its Saved Game data and can be exploited by loading a malicious load file.

Another example of a stack-based buffer overflow exploit was used to gain kernel-level access on the original Nintendo Wii, which also allowed the use of pirated games and the installation of unsigned software. The Twilight Hack exploits a vulnerability found in "The Legend of Zelda: Twilight Princess" game and is also exploited by loading malicious Saved Game data, by using a long name for Link's horse "Epona".

Finally, in 2020 a new vulnerability was found for the PlayStation 2, almost 20 years after its initial release. The FreeDVDBoot exploits a vulnerability in the PS2's DVD player by placing a malicious "VIDEO_TS.IFO" file. This gets read by the DVD player and causes an overflow that can lead to code execution. This was the first-ever PS2 hack that is entirely software-based, as all older hacks utilized some form of hardware like a malicious memory card to load and execute unsigned software.

Of course, operating systems like Windows, Linux, and macOS were always the first target for stack-based buffer overflow exploits. There have been numerous such vulnerabilities found in all of these systems and software running on them. By detecting these vulnerabilities before products go into production, we would reduce the occurrence of potentially catastrophic pitfalls.


Stack Overflow Protections

As we may notice from the above examples, most of them are pretty old, aging back at least a decade. This is because modern operating systems have many protections for the stack, like preventing code execution or randomly changing the memory addresses. These protections make it so we cannot easily run our code placed on the stack or pre-calculate the memory address to jump to.

However, even with these types of protections, if a program is vulnerable to a Buffer Overflow, there are advanced methods to bypass these protections. Some examples include the previously mentioned Return Oriented Programming (ROP) or Windows-specific exploitation methods like Egg Hunting or Structured Exception Handling (SEH) exploitation.

Furthermore, modern compilers prevent the usage of functions that are vulnerable to Stack overflows, which significantly reduces the occurrence of stack-based buffer overflows. This is why stack-based buffer overflows are less common these days. At the same time, other more advanced types of binary exploitation are more common, as they can't be mitigated by simply enabling a protection method.


Why Learn Basic Stack Overflows?

In this module, we'll learn how to gain code execution through basic stack-based buffer overflows. We will do so on applications and systems that do not have any memory protection. Otherwise, we'd require more advanced methods to gain code execution.

But if basic stack-based overflows are no longer common these days, then why should we learn them?
We do so because learning them gives us a good understanding of the basics of binary exploitation and the fundamentals of exploit development.

Furthermore, once we master how to detect and exploit basic stack-based buffer overflows, it will be much easier to learn Structured Exception Handling (SEH), which is very common in modern Windows systems.

Finally, once we get a good grip on basic stack overflows and basic mitigation bypasses, we would be ready to start learning advanced mitigation bypass methods, like (ROP) and other advanced binary exploitation methods.

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Relevant Paths

This module progresses you towards the following Paths

Intro to Binary Exploitation

Binary exploitation is a core tenet of penetration testing, but learning it can be daunting. This is mainly due to the complexity of binary files and their underlying machine code and how binary files interact with computer memory and the processor. To learn the basics of binary exploitation, we must first have a firm grasp of Computer Architecture and the Assembly Language. To move into more advanced binary exploitation, we must have a firm grasp on basic buffer overflow attacks, principles such as CPU architecture, and CPU registers for 32-bit Windows and Linux systems. Furthermore, a strong foundation in Python scripting is essential for writing and understanding exploit scripts.

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Reward: +50
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Buffer overflows are common vulnerabilities in software applications that can be exploited to achieve remote code execution (RCE) or perform a Denial-of-Service (DoS) attack. These vulnerabilities are caused by insecure coding, resulting in an attacker being able to overrun a program's buffer and overwrite adjacent memory locations, changing the program's execution path and resulting in unintended actions.
Medium
Path Sections 11 Sections
Reward: +10
This module is your first step into Windows Binary Exploitation, and it will teach you how to exploit local and remote buffer overflow vulnerabilities on Windows machines.

CREST CPSA/CRT Preparation

This is a skill path to prepare you for CREST's CPSA and CRT exams. The following CPSA/CRT syllabus areas (IDs) are covered: A1, A2, A3, A4, A5, B1, B4, B5, B6, B8, B9, B13, B14, C1, C2, C3, C4, D1, D2, E1, E2, E3, E4, E5, E9, F1, F2, F3, F4, F5, F6, F7, F8, F9, G1, G2, G4, G5, G6, G7, G8, G9, H1, H2, H3, H4, H5, H6, H8, H9, H10, H11, H12, H13, I1, I2, I3, I6, J1, J2, J3. Take your time to complete all related sections and when you are ready you can book your CREST exam through the following links. CREST CPSA: https://www.crest-approved.org/certification-careers/crest-certifications/crest-practitioner-security-analyst/. CREST CRT: https://www.crest-approved.org/certification-careers/crest-certifications/crest-registered-penetration-tester/.

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Path Sections 28 Sections
Reward: +20 UPDATED
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Medium
Path Sections 33 Sections
Reward: +20 UPDATED
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Hard
Path Sections 23 Sections
Reward: +100
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Hard
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DACL Attacks I
Mini-Module
Hard
Path Sections 7 Sections
Reward: +100
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Medium
Path Sections 13 Sections
Reward: +10
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Medium
Path Sections 11 Sections
Reward: +10
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Easy
Path Sections 15 Sections
Reward: +20
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Easy
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Path Sections 14 Sections
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Medium
Path Sections 17 Sections
Reward: +10
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Path Sections 11 Sections
Reward: +20
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Medium
Path Sections 11 Sections
Reward: +10
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Medium
Path Sections 11 Sections
Reward: +20
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Medium
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Reward: +20
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Medium
Path Sections 14 Sections
Reward: +20
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Medium
Path Sections 18 Sections
Reward: +20
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Medium
Path Sections 33 Sections
Reward: +20 UPDATED
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Medium
Path Sections 13 Sections
Reward: +20
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Hard
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Reward: +100
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Path Sections 12 Sections
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Hard
Path Sections 21 Sections
Reward: +100 NEW
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Easy
Path Sections 16 Sections
Reward: +20
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Easy
Path Sections 8 Sections
Reward: +20
Proper documentation is paramount during any engagement. The end goal of a technical assessment is the report deliverable which will often be presented to a broad audience within the target organization. We must take detailed notes and be very organized in our documentation, which will help us in the event of an incident during the assessment. This will also help ensure that our reports contain enough detail to illustrate the impact of our findings properly.

CREST CCT INF Preparation

This is a skill path to prepare you for CREST's CCT INF exam. The following CCT INF syllabus areas (IDs) are covered: A1, A2, A3, A4, A5, A8, A9, A10, B1, B2, B4, B5, C1, C2, C3, C4, C6, C7, D1, D2, D5, D9, D10, D13, D14, D15, D18, D19, E1, E2, E3 E6, E7, E8, E9, E11, E13, E14, E15, E16, E17, E18, E19, E20, E25, E26, F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, F13, F15, F16, G1, G2, G3, G4, G5, G6, G7, G8, H1, H2, H3, H4, H5, H6, H7, H8, H9, H10, H11, H12, H13, H14, H15, H16, H17, H19, H20, H21, H23, H24, H25, H26, H27, H28, H29, H30, H31, H32, H33, H34, H35, H36, H37, H38, H40, I1, I2, I3, I4, I6, K1, K2, K3, K4, N1, N2. Take your time to complete all related sections and when you are ready you can book your CREST exam through the following link. https://www.crest-approved.org/certification-careers/crest-certifications/crest-certified-infrastructure-tester/

Hard Path Sections 945 Sections
Required: 12510
Reward: +2630
Path Modules
Fundamental
Path Sections 21 Sections
Reward: +10 UPDATED
As an information security professional, a firm grasp of networking fundamentals and the required components is necessary. Without a strong foundation in networking, it will be tough to progress in any area of information security. Understanding how a network is structured and how the communication between the individual hosts and servers takes place using the various protocols allows us to understand the entire network structure and its network traffic in detail and how different communication standards are handled. This knowledge is essential to create our tools and to interact with the protocols.
Fundamental
Path Sections 8 Sections
Reward: +10
This module introduces the topic of HTTP web requests and how different web applications utilize them to communicate with their backends.
Fundamental
Path Sections 17 Sections
Reward: +10
In the Introduction to Web Applications module, you will learn all of the basics of how web applications work and begin to look at them from an information security perspective.
Fundamental
Path Sections 30 Sections
Reward: +10 UPDATED
This module covers the fundamentals required to work comfortably with the Linux operating system and shell.
Fundamental
Path Sections 14 Sections
Reward: +10
This module covers the fundamentals required to work comfortably with the Windows operating system.
Easy
Path Sections 23 Sections
Reward: +10
As administrators and Pentesters, we may not always be able to utilize a graphical user interface for the actions we need to perform. Introduction to Windows Command Line aims to introduce students to the wide range of uses for Command Prompt and PowerShell within a Windows environment. We will cover basic usage of both key executables for administration, useful PowerShell cmdlets and modules, and different ways to leverage these tools to our benefit.
Medium
Path Sections 15 Sections
Reward: +10
Network traffic analysis is used by security teams to monitor network activity and look for anomalies that could indicate security and operational issues. Offensive security practitioners can use network traffic analysis to search for sensitive data such as credentials, hidden applications, reachable network segments, or other potentially sensitive information "on the wire." Network traffic analysis has many uses for attackers and defenders alike.
Medium
Path Sections 8 Sections
Reward: +10
This mini-module concisely introduces hardware attacks, covering Bluetooth risks and attacks, Cryptanalysis Side-Channel Attacks, and vulnerabilities like Spectre and Meltdown. It delves into both historical and modern Bluetooth hacking techniques, explores the principles of cryptanalysis and different side-channel attacks, and outlines microprocessor design, optimisation strategies and vulnerabilities, such as Spectre and Meltdown.
Fundamental
Path Sections 15 Sections
Reward: +10 UPDATED
This module teaches the penetration testing process broken down into each stage and discussed in detail. We will cover many aspects of the role of a penetration tester during a penetration test, explained and illustrated with detailed examples. The module also covers pre-engagement steps like the criteria for establishing a contract with a client for a penetration testing engagement.
Easy
Path Sections 12 Sections
Reward: +10
Nmap is one of the most used networking mapping and discovery tools because of its accurate results and efficiency. The tool is widely used by both offensive and defensive security practitioners. This module covers fundamentals that will be needed to use the Nmap tool for performing effective network enumeration.
Medium
Path Sections 21 Sections
Reward: +20 UPDATED
This module covers techniques for footprinting the most commonly used services in almost all enterprise and business IT infrastructures. Footprinting is an essential phase of any penetration test or security audit to identify and prevent information disclosure. Using this process, we examine the individual services and attempt to obtain as much information from them as possible.
Easy
Path Sections 10 Sections
Reward: +20
This module covers techniques for identifying and analyzing an organization's web application-based attack surface and tech stack. Information gathering is an essential part of any web application penetration test, and it can be performed either passively or actively.
Hard
Path Sections 23 Sections
Reward: +200
OSINT (Open-source Intelligence) is a crucial stage of the penetration testing process. A thorough examination of publicly available information can increase the chances of finding a vulnerable system, gaining valid credentials through password spraying, or gaining a foothold via social engineering. There is a vast amount of publicly available information from which relevant information needs to be selected.
Easy
Path Sections 17 Sections
Reward: +10
This module introduces the concept of Vulnerability Assessments. We will review the differences between vulnerability assessments and penetration tests, how to carry out a vulnerability assessment, how to interpret the assessment results, and how to deliver an effective vulnerability assessment report.
Medium
Path Sections 10 Sections
Reward: +10
During an assessment, it is very common for us to transfer files to and from a target system. This module covers file transfer techniques leveraging tools commonly available across all versions of Windows and Linux systems.
Medium
Path Sections 17 Sections
Reward: +10
Gain the knowledge and skills to identify and use shells & payloads to establish a foothold on vulnerable Windows & Linux systems. This module utilizes a fictitious scenario where the learner will place themselves in the perspective of a sysadmin trying out for a position on CAT5 Security's network penetration testing team.
Easy
Path Sections 15 Sections
Reward: +10
The Metasploit Framework is an open-source set of tools used for network enumeration, attacks, testing security vulnerabilities, evading detection, performing privilege escalation attacks, and performing post-exploitation.
Medium
Path Sections 22 Sections
Reward: +10 UPDATED
Passwords are still the primary method of authentication in corporate networks. If strong password policies are not in place, users will often opt for weak, easy-to-remember passwords that can often be cracked offline and used to further our access. We will encounter passwords in many forms during our assessments. We must understand the various ways they are stored, how they can be retrieved, methods to crack weak passwords, ways to use hashes that cannot be cracked, and hunting for weak/default password usage.
Medium
Path Sections 19 Sections
Reward: +20
Organizations regularly use a standard set of services for different purposes. It is vital to conduct penetration testing activities on each service internally and externally to ensure that they are not introducing security threats. This module will cover how to enumerate each service and test it against known vulnerabilities and exploits with a standard set of tools.
Medium
Path Sections 14 Sections
Reward: +20
This module covers the fundamentals of password cracking using the Hashcat tool.
Fundamental
Path Sections 16 Sections
Reward: +10
Active Directory (AD) is present in the majority of corporate environments. Due to its many features and complexity, it presents a vast attack surface. To be successful as penetration testers and information security professionals, we must have a firm understanding of Active Directory fundamentals, AD structures, functionality, common AD flaws, misconfigurations, and defensive measures.
Medium
Path Sections 12 Sections
Reward: +200
This module provides an overview of Active Directory (AD), introduces core AD enumeration concepts, and covers enumeration with built-in tools.
Medium
Path Sections 9 Sections
Reward: +200
This module covers AD enumeration focusing on the PowerView and SharpView tools. We will cover various techniques for enumerating key AD objects that will inform our attacks in later modules.
Medium
Path Sections 14 Sections
Reward: +100 UPDATED
This module covers AD enumeration focusing on the BloodHound tool. We will cover various techniques for enumerating key AD objects that will inform our attacks in later modules.
Medium
Path Sections 18 Sections
Reward: +20
Once a foothold is gained during an assessment, it may be in scope to move laterally and vertically within a target network. Using one compromised machine to access another is called pivoting and allows us to access networks and resources that are not directly accessible to us through the compromised host. Port forwarding accepts the traffic on a given IP address and port and redirects it to a different IP address and port combination. Tunneling is a technique that allows us to encapsulate traffic within another protocol so that it looks like a benign traffic stream.
Medium
Path Sections 36 Sections
Reward: +20
Active Directory (AD) is the leading enterprise domain management suite, providing identity and access management, centralized domain administration, authentication, and much more. Due to the many features and complexity of AD, it presents a large attack surface that is difficult to secure properly. To be successful as infosec professionals, we must understand AD architectures and how to secure our enterprise environments. As Penetration testers, having a firm grasp of what tools, techniques, and procedures are available to us for enumerating and attacking AD environments and commonly seen AD misconfigurations is a must.
Hard
Path Sections 23 Sections
Reward: +100
Kerberos is an authentication protocol that allows users to authenticate and access services on a potentially insecure network. Due to its prevalence throughout an Active Directory environment, it presents us with a significant attack surface when assessing internal networks. This module will explain how Kerberos works thoroughly and examines several scenarios to practice the most common attacks against it from multiple perspectives.
DACL Attacks I
Mini-Module
Hard
Path Sections 7 Sections
Reward: +100
Discretionary Access Control Lists (DACLs), found within security descriptors, are a fundamental component of the security model of Windows and Active Directory, defining and enforcing access to the various system resources. This mini-module will cover enumerating and attacking common DACL misconfigurations, allowing us to escalate our privileges horizontally and vertically and move laterally across an Active Directory network.
Medium
Path Sections 27 Sections
Reward: +100
Active Directory presents a vast attack surface and often requires us to use many different tools during an assessment. The CrackMapExec tool, known as a "Swiss Army Knife" for testing networks, facilitates enumeration, attacks, and post-exploitation that can be leveraged against most any domain using multiple network protocols. It is a versatile and highly customizable tool that should be in any penetration tester's toolbox.
Easy
Path Sections 28 Sections
Reward: +20 UPDATED
Privilege escalation is a crucial phase during any security assessment. During this phase, we attempt to gain access to additional users, hosts, and resources to move closer to the assessment's overall goal. There are many ways to escalate privileges. This module aims to cover the most common methods emphasizing real-world misconfigurations and flaws that we may encounter in a client environment. The techniques covered in this module are not an exhaustive list of all possibilities and aim to avoid extreme "edge-case" tactics that may be seen in a Capture the Flag (CTF) exercise.
Medium
Path Sections 33 Sections
Reward: +20 UPDATED
After gaining a foothold, elevating our privileges will provide more options for persistence and may reveal information stored locally that can further our access in the environment. Enumeration is the key to privilege escalation. When you gain initial shell access to the host, it is important to gain situational awareness and uncover details relating to the OS version, patch level, any installed software, our current privileges, group memberships, and more. Windows presents an enormous attack surface and, being that most companies run Windows hosts in some way, we will more often than not find ourselves gaining access to Windows machines during our assessments. This covers common methods while emphasizing real-world misconfigurations and flaws that we may encounter during an assessment. There are many additional "edge-case" possibilities not covered in this module. We will cover both modern and legacy Windows Server and Desktop versions that may be present in a client environment.
Medium
Path Sections 13 Sections
Reward: +10
Buffer overflows are common vulnerabilities in software applications that can be exploited to achieve remote code execution (RCE) or perform a Denial-of-Service (DoS) attack. These vulnerabilities are caused by insecure coding, resulting in an attacker being able to overrun a program's buffer and overwrite adjacent memory locations, changing the program's execution path and resulting in unintended actions.
Medium
Path Sections 11 Sections
Reward: +10
This module is your first step into Windows Binary Exploitation, and it will teach you how to exploit local and remote buffer overflow vulnerabilities on Windows machines.
Easy
Path Sections 15 Sections
Reward: +20
Web application penetration testing frameworks are an essential part of any web penetration test. This module will teach you two of the best frameworks: Burp Suite and OWASP ZAP.
Easy
Path Sections 13 Sections
Reward: +10
This module covers the fundamental enumeration skills of web fuzzing and directory brute forcing using the Ffuf tool. The techniques learned in this module will help us in locating hidden pages, directories, and parameters when targeting web applications.
Easy
Path Sections 11 Sections
Reward: +20
Learn how to brute force logins for various types of services and create custom wordlists based on your target.
Easy
Path Sections 10 Sections
Reward: +20
Cross-Site Scripting (XSS) vulnerabilities are among the most common web application vulnerabilities. An XSS vulnerability may allow an attacker to execute arbitrary JavaScript code within the target's browser and result in complete web application compromise if chained together with other vulnerabilities. This module will teach you how to identify XSS vulnerabilities and exploit them.
Medium
Path Sections 14 Sections
Reward: +20
Maintaining and keeping track of a user's session is an integral part of web applications. It is an area that requires extensive testing to ensure it is set up robustly and securely. This module covers the most common attacks and vulnerabilities that can affect web application sessions, such as Session Hijacking, Session Fixation, Cross-Site Request Forgery, Cross-Site Scripting, and Open Redirects.
Medium
Path Sections 17 Sections
Reward: +10
Databases are an important part of web application infrastructure and SQL (Structured Query Language) to store, retrieve, and manipulate information stored in them. SQL injection is a code injection technique used to take advantage of coding vulnerabilities and inject SQL queries via an application to bypass authentication, retrieve data from the back-end database, or achieve code execution on the underlying server.
Easy
Path Sections 11 Sections
Reward: +20
The SQLMap Essentials module will teach you the basics of using SQLMap to discover various types of SQL Injection vulnerabilities, all the way to the advanced enumeration of databases to retrieve all data of interest.
Hard
Path Sections 16 Sections
Reward: +100
In this module, we cover blind SQL injection attacks and MSSQL-specific attacks.
Hard
Path Sections 12 Sections
Reward: +100
This module covers advanced SQL injection techniques with a focus on white-box testing, Java/Spring and PostgreSQL.
Medium
Path Sections 12 Sections
Reward: +100
In this module, we will look at exploiting NoSQL injection vulnerabilities, specifically MongoDB, with examples in Python, PHP, and Node.JS.
Medium
Path Sections 11 Sections
Reward: +10
File Inclusion is a common web application vulnerability, which can be easily overlooked as part of a web application's functionality.
Medium
Path Sections 11 Sections
Reward: +20
Arbitrary file uploads are among the most critical web vulnerabilities. These flaws enable attackers to upload malicious files, execute arbitrary commands on the back-end server, and even take control over the entire server and all web applications hosted on it and potentially gain access to sensitive data or cause a service disruption.
Medium
Path Sections 12 Sections
Reward: +20
Command injection vulnerabilities can be leveraged to compromise a hosting server and its entire network. This module will teach you how to identify and exploit command injection vulnerabilities and how to use various filter bypassing techniques to avoid security mitigations.
Medium
Path Sections 14 Sections
Reward: +20
Authentication is probably the most straightforward and prevalent measure used to secure access to resources, and it's the first line of defense against unauthorized access. Broken authentication is currently listed as #7 on the 2021 OWASP Top 10 Web Application Security Risks, falling under the broader category of Identification and Authentication failures. A vulnerability or misconfiguration at the authentication stage can devastatingly impact an application's overall security.
Medium
Path Sections 18 Sections
Reward: +20
This module covers three common web vulnerabilities, HTTP Verb Tampering, IDOR, and XXE, each of which can have a significant impact on a company's systems. We will cover how to identify, exploit, and prevent each of them through various methods.
Medium
Path Sections 15 Sections
Reward: +100
This module covers details on Transport Layer Security (TLS) and how it helps to make HTTP secure with the widely used HTTPS. That includes how TLS works, how TLS sessions are established, common TLS misconfigurations, as well as famous attacks on TLS. We will discuss how to identify, exploit, and prevent TLS attacks.
Hard
Path Sections 18 Sections
Reward: +100
This module covers three HTTP vulnerabilities: CRLF Injection, HTTP Request Smuggling, and HTTP/2 Downgrading. These vulnerabilities can arise on the HTTP level in real-world deployment settings utilizing intermediary systems such as reverse proxies in front of the web server. We will cover how to identify, exploit, and prevent each of these vulnerabilities.
Medium
Path Sections 15 Sections
Reward: +100
This module covers three injection attacks: XPath injection, LDAP injection, and HTML injection in PDF generation libraries. While XPath and LDAP injection vulnerabilities can lead to authentication bypasses and data exfiltration, HTML injection in PDF generation libraries can lead to Server-Side Request Forgery (SSRF), Local File Inclusion (LFI), and other common web vulnerabilities. We will cover how to identify, exploit, and prevent each of these injection attacks.
Hard
Path Sections 20 Sections
Reward: +100
This module covers three common HTTP vulnerabilities: Web Cache Poisoning, Host Header Vulnerabilities, and Session Puzzling or Session Variable Overloading. These vulnerabilities can arise on the HTTP level due to web server misconfigurations, other systems that have to be considered during real-world deployment such as web caches, or coding mistakes in the web application. We will cover how to identify, exploit, and prevent each of these vulnerabilities.
Medium
Path Sections 33 Sections
Reward: +20 UPDATED
Penetration Testers can come across various applications, such as Content Management Systems, custom web applications, internal portals used by developers and sysadmins, and more. It's common to find the same applications across many different environments. While an application may not be vulnerable in one environment, it may be misconfigured or unpatched in the next. It is important as an assessor to have a firm grasp of enumerating and attacking the common applications discussed in this module. This knowledge will help when encountering other types of applications during assessments.
Medium
Path Sections 13 Sections
Reward: +20
Web services and APIs are frequently exposed to provide certain functionalities in a programmatic way between heterogeneous devices and software components. Both web services and APIs can assist in integrating different applications or facilitate separation within a given application. This module covers how to identify the functionality a web service or API offers and exploit any security-related inefficiencies.
Easy
Path Sections 16 Sections
Reward: +20
WordPress is an open-source Content Management System (CMS) that can be used for multiple purposes.
Easy
Path Sections 8 Sections
Reward: +20
Proper documentation is paramount during any engagement. The end goal of a technical assessment is the report deliverable which will often be presented to a broad audience within the target organization. We must take detailed notes and be very organized in our documentation, which will help us in the event of an incident during the assessment. This will also help ensure that our reports contain enough detail to illustrate the impact of our findings properly.
Hard
Path Sections 17 Sections
Reward: +200
Learn how to improve your JavaScript code's security through Code Review, Static/Dynamic Analysis, Vulnerability Identification, and Patching.
Hard
Path Sections 15 Sections
Reward: +100
This module explores several web vulnerabilities from a whitebox approach: Prototype Pollution, Timing Attacks & Race Conditions, and those arising from Type Juggling. We will discuss how to identify, exploit, and prevent each vulnerability.