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Re: Arbitrary code execution in eping plugin

oliver@xxxxxxxxxxxxx wrote:

Hello,

the problem is in function eping_validaddr() in functions.php where the host is 
checked if it is valid as the name says...
But the only check is to see if it is a valid ip adress for eping, here is the 
code:

--------------8<-----------------------------------------8<-------------------------------------
function eping_validaddr($eping_hosttocheck)
{
If 
(ereg("(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)",
 $eping_hosttocheck))
   {
       return true;
   }
   else
   {
       return false;
   }
--------------8<-----------------------------------------8<-------------------------------------

I am sorry but I am a coder and my eyes are bleeding when looking at stuff like 
that so here is my suggestion for replaceing the if-statement:
if(preg_match("/^[0-9]{2,3}?\.[0-9]{1,3}?\.[0-9]{1,3}?\.[0-9]{1,3}?$/", 
$eping_hosttocheck))
Your suggestion would block 1.1.1.1 which is a valid IP, while letting through 999.999.999.999 which isn't. It's a bad regex for finding valid IP's.
Implementing an inet_aton()-like function would be several orders of magnitude faster than a preg_match() and several times more accurate. 


So only IP-Adresses are allowed and no kind of code injection is possible.

And everyone who thinks 'will he ever stop writeing?' will be disappointed:
The same vulnerability also exists in the eTrace modul from E107. It looks like 
the same Author of the ePing modul.
The only difference is the you have to search for 'etrace' instead of 'eping' 
in the files

Greetings from Germany
Oliver