Re:Potential hole in Ettercap 0.6.2

From: Jose Nazario (joseat_private)
Date: Tue Dec 04 2001 - 13:44:41 PST

  • Next message: zeno: "IE Denial of service (sorta)"

    On Tue, 4 Dec 2001, ALoR wrote:
    
    > <full disclosure>
    > the problem was a forgotten "printf(buffer)" in the Interface_WExit(char
    > *buffer) function.
    > so to fix it simply replace the line 1252 of ec_interface.c with
    > printf("%s", buffer);
    > </full disclosure>
    
    among other problems. analysis of the gobbles exploit [1] shows its abuse
    of the update process that gets done. in src/ec_main.c:
    
    
        441 void Main_Check_NewRelease(void)
    	[snip]
        532          if (answer == 'y' || answer == 'Y')
        533          {
        534             char wget[100];
        535             sprintf(wget, "wget
    http://%s/download/ettercap-%s.tar.gz", host, latest);
        536             system(wget);
        537          }
    
    
    so i set my path to be .:$PATH and make my own wget, and what gets
    executed is ./wget. an example one i got to work is:
    
    	#!/bin/sh
    	id
    
    it honors the permissions of the caller ... this is just executing
    ettercap -v, the update path ...
    
    yeah. there are some format string problems. and there are probably a
    bunch of other problems. the one gobbles was seeing was likely caused by
    the error function 'void Error_msg(char *message, ...)' which doesn't do
    any formatting.
    
    you have many issues to fix in the code, it appears. i would disblae the
    suid option. yeah, its moronic to install it suid root. however even
    marginaly respecting it (and dropping your priv checks) is a bad idea
    until you can more agressively audit the code, a time consuming process,
    yes. it's a nice tool, i hope you can fix the problems in it.
    
    notes
    
    [1] if you dont know where to get gobbles goods by now ... pay more
    attention.
    
    
    ____________________________
    jose nazario						     joseat_private
    	      	     PGP: 89 B0 81 DA 5B FD 7E 00  99 C3 B2 CD 48 A0 07 80
    				       PGP key ID 0xFD37F4E5 (pgp.mit.edu)
    



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