Improper input validation

Improper input validation means not checking the things that people put in when they use a computer program or a website or other kinds of technology. People might put in all kinds of things like words, numbers, or symbols, and the program needs to make sure that what they put in is okay and won't cause any problems or let bad people do bad things. Just like when you put a puzzle piece where it doesn't belong, it can mess up the whole picture, putting bad things in a program can mess up the whole program, and that's not good. So, programmers need to make sure that the program is checking and validating all the input they get to make sure it's good input. Otherwise, the program can do things it's not supposed to, and bad people can try to trick the program into doing something bad too. So it's really important to make sure that the program checks everything that goes into it so it can work properly and something bad doesn't happen.