Buffer overflows are a type of reverse engineering attacks in which one manipulates the instructions in an application for potentially malicious purposes.
There can be more types of buffer overflow but two common are remote and local. Let's take for example local buffer overflow?
What's the purpose of it? Well, if you are on a system as a low privilege user and the system runs an application that is vulnerable to buffer overflow, you could exploit the buffer overflow and escalate your privileges on the system; by, for example, throwing a root shell.
In this video, folks at Computerphile, thoroughly and graphically explain what happens in a buffer overflow attack. Assistant Professor Dr. Mike Pound also demonstrate who instructions are executed in a program using gdb, a command line debugger in linux.
Personally, at one point, I am really interested in getting into and learning reverse engineering as I find it really important in cybersecurity (a field that I'm training myself for), especially when it comes to malware analysis. For now, I'm training on vulnerable virtual machines to obtain a shell and escalate my privileges to root.
Anyway, if you're a geek and you want to understand buffer overflow attacks, this 20 minute long video is a very good start!
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Cristi Vlad Self-Experimenter and Author