Why do signature extension errors have high security risks?

Question

Can someone explain why sign extension errors in any c, C ++ programs have high security risks?

I read that sign extension errors "can often create buffer overflows and other memory based problems".

I read this article on Google,

http://minsky.gsi.dit.upm.es/semanticwiki/index.php/Sign_extension_error

But I could not understand how this affects any application, how can an attacker exploit this type of vulnerability?

Thanks Advance,

Answer 1

char . char C , a > 0x7F . . C unsigned char .