CYBERSECURITY FOR BEGINNERS: A Practical Guide to Protecting Your Online Identity and Data (2024 Crash Course)

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Chapter 1 Software Bugs and Buffer Overflow

Software defects are the first vulnerability I wanted to discuss with you. A software bug is, in short, an error in a computer program that makes it behave in a way that it wasn’t meant to. This might be as straightforward as a bug in the software’s logic.

Calculation error

For instance, you would not anticipate results if an Excel spreadsheet multiplied the numbers together instead of adding them, when it was meant to take the contents of two cells, add them, and put that value in a third cell. We refer to this as a computation error. You are anticipating that the third cell will yield the total of the first two cells. That is an example of a bug since the application did not function as the person who wrote it planned.

Buffer overflow

A buffer overflow is another type of software issue. A buffer is a section of memory set aside to hold a certain quantity of data. If there is more data than the memory buffer can hold, buffer overflow may happen. A form that you may have filled out with your name and address and that contains a few rows of boxes is an example of this happening outside of computers. You are only allowed to enter one letter or one number in each box while completing these forms. When completing the form, if your last name is longer than the person who created it allowed for,

Confusion results from this. Where should your first name be entered? Do you simply go on and make a space? What happens if that gets too lengthy and crosses over into the space of the following box? When someone reads the form, will they assume that you meant to write over the box in the other section? Similar to this, computer software employs buffers to store different types of data in memory when it writes to a memory stack. These buffers are positioned adjacent to one another.

Consequently, just as a form has a set number of boxes for the last name, address, and other fields, so too does each buffer have a set number of bits that will be utilized to hold the data if there are several distinct values in each buffer.

Why is it vital for me to know about seemingly insignificant issues like spreadsheet malfunctions or data that exceeds the buffer allocated for it, you may be wondering. True, most of the time the worst that may happen with software problems is only frustration; furthermore, the bug is probably not even discovered.

However, you also need to be aware that malevolent attackers can use these vulnerabilities to trick programs into doing what they want. An experienced attacker could use their understanding of the bug to exploit it in a way that could be advantageous rather than just having a minor