Many protocols read values of a network to specify how much is left in the packet (it's how packet boundaries are usually encoded, specifically in SMB1/2/3).Sure. So do many other protocols and file formats. But if you're using those values for memory allocation without checking them first then getting a 0 might be the least of your worries. Unchecked large values might be a DoS attack waiting to happen.
If you work with C code where security is a factor then surely you already know this so it still seems odd to put so much emphasis on your original question. You do you I guess. :-)
