[UPHPU] Using exec() to ping?

[dataw0lf]

Jordan S. Jones wrote:

> Wouldn't chmod o+x `which ping` work just as well?


No.  It's not a problem with actually executing the file.  It's a 
problem with permissions inside the ping program to access a raw 
socket.  Since the dawn of Unix time, you've had to be root to invoke a 
raw socket.  This means that normally, if you execute a program as a 
normal user, you won't have those permissions.  However, the suid bit 
forces the applicable program to run under the OWNER of the program 
(obviously, in this case, root), giving it the permissions inherent with 
that owner.  Basically, it's a way to tell the ping program to hijack 
itself to be run as root, and then return to the executing owner.