Course: Linux Exploits & Mitigation

Analyzing kernel vulnerabilities requires an environment to carry out the reproduction of exploits. Being able to quickly and securely stage an operating system is essential. In this course, you'll explore virtual environments and stage systems using QEMU.

You'll develop an approach to setting up virtual environments for the Linux kernel, complete with network support. You'll install Linux kernels by version and compile Linux kernels from scratch. Next, you'll investigate architectural considerations, emulate architectures in QEMU, and gather system info from your staging environment.

Finally, you'll examine vulnerability considerations that might affect the virtual environment itself and identify safeguards for protecting your computing environments when carrying out exploit analysis.

By the end of this course, you'll be able to launch an instance of Alpine Linux, configure networking options, and emulate an Alpine Linux ARM variant within a QEMU environment.

Navigating the space between userland and kernel and how it impacts how programs reside and execute inside of an operating system can lead to a better understanding of how it's exploited. Being able to debug, disassemble, and dump programs are essential to finding vulnerabilities. In this course, you'll investigate the structure of the Linux kernel, system calls, and program interfaces by running, debugging, and disassembling code.

You'll explore how programs fit in memory and how they are protected and executed. You'll debug and disassemble code into its assembly for inspection. Next, you'll explore the GNU C implementation of the standard library and interface using syscalls and the Linux system call table. Finally, you'll explore how programs and scripts are executed and how they are segmented in memory.

String vulnerabilities are at the core of a wide range of exploits. Being able to recognize, debug, and fix unsafe string manipulation code is essential to avoiding vulnerabilities. In this course, you'll explore how string code can be written safely and how strings vulnerabilities are exploited.

You'll look at the most common format string vulnerabilities in the C programming language and what it means to overflow a string buffer. You'll debug string exploits, including vulnerabilities introduced by common string output and manipulation functions. Next, you'll correct common errors, check strings for safety, loop over strings, and see what happens when unsafe strings are executed in a program. Finally, you'll describe how code can be injected via strings and how strings can be returned safely.

• Memory and pointer vulnerabilities come from a number of common

• programmer mistakes. Being able to recognize, debug, and fix unsafe
• memory allocation and access errors is essential to avoiding
• vulnerabilities. In this course, you'll explore how memory and
• pointer vulnerabilities arise and how they lead to program errors
• and exploits. You'll look at how memory is allocated and accessed
• in a typical C program. You'll investigate what causes heap and
• stack overflows, use-after-free (UAF) vulnerabilities, and
• out-of-bounds access errors. In addition, you'll recognize dangling
• pointers, NULL dereferences, and off-by-one loops. Finally, you'll
• delve into how coding errors lead to corrupted memory and arbitrary
• code execution.

• The baseline of security for any computer system is a defense

• against known exploits and attacks. In this course, you'll learn
• how to employ the core pentesting tools to help validate that your
• systems and software are secure against known attacks. You'll start
• by learning how to leverage the capabilities of Metasploit by using
• its basic commands, payloads, and options. You'll then explore
• Metasploitable, Commix, as well as Exploit Database, SearchSploit,
• and the Linux Exploit Suggester. Next, you'll learn how to use
• RouterSploit and ShellNoob to carry out tests. Finally, you'll
• examine how to use SQLMap to explore how SQL injection attacks are
• formed and how to protect against them.

• Vulnerabilities vary by architecture and family of processor.

• Recognizing the processor implementations and the differences that
• lead to an exploit is essential. In this course, you'll explore
• different classes of vulnerabilities based on the computing
• environment. You'll learn about the architectural differences and
• system implementations that lead to race conditions, shellcode and
• out-of-order execution vulnerabilities. You'll explore mitigations
• and protections to prevent stack smashing, use-after-free, and
• integer vulnerabilities. Next, you'll examine contemporary exploits
• such as Spectre and Meltdown and mitigations provided by Write XOR
• Execute (W^X). Finally, you'll investigate protections to prevent
• privileged escalation and exploiting processes and tasks.